Adding upstream version 124.0.1.upstream/124.0.1

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

28 files changed, 5419 insertions, 0 deletions

diff --git a/browser/components/screenshots/tests/browser/browser.toml b/browser/components/screenshots/tests/browser/browser.toml
new file mode 100644
index 0000000000..b363c14732
--- /dev/null
+++ b/browser/components/screenshots/tests/browser/browser.toml
@@ -0,0 +1,55 @@
+[DEFAULT]
+support-files = [
+  "head.js",
+  "iframe-test-page.html",
+  "first-iframe.html",
+  "second-iframe.html",
+  "test-page.html",
+  "short-test-page.html",
+  "large-test-page.html",
+  "test-page-resize.html",
+]
+
+prefs = [
+  "extensions.screenshots.disabled=false",
+  "screenshots.browser.component.enabled=true",
+]
+
+["browser_iframe_test.js"]
+
+["browser_overlay_keyboard_test.js"]
+
+["browser_screenshots_drag_scroll_test.js"]
+
+["browser_screenshots_drag_test.js"]
+
+["browser_screenshots_focus_test.js"]
+
+["browser_screenshots_overlay_panel_sync.js"]
+
+["browser_screenshots_page_unload.js"]
+
+["browser_screenshots_short_page_test.js"]
+
+["browser_screenshots_telemetry_tests.js"]
+
+["browser_screenshots_test_downloads.js"]
+
+["browser_screenshots_test_escape.js"]
+
+["browser_screenshots_test_full_page.js"]
+
+["browser_screenshots_test_page_crash.js"]
+skip-if = ["!crashreporter"]
+
+["browser_screenshots_test_screenshot_too_big.js"]
+
+["browser_screenshots_test_toggle_pref.js"]
+
+["browser_screenshots_test_toolbar_button.js"]
+
+["browser_screenshots_test_visible.js"]
+
+["browser_test_element_picker.js"]
+
+["browser_test_resize.js"]
diff --git a/browser/components/screenshots/tests/browser/browser_iframe_test.js b/browser/components/screenshots/tests/browser/browser_iframe_test.js
new file mode 100644
index 0000000000..bb853fbe28
--- /dev/null
+++ b/browser/components/screenshots/tests/browser/browser_iframe_test.js
@@ -0,0 +1,123 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+add_task(async function test_selectingElementsInIframes() {
+  await BrowserTestUtils.withNewTab(
+    {
+      gBrowser,
+      url: IFRAME_TEST_PAGE,
+    },
+    async browser => {
+      let helper = new ScreenshotsHelper(browser);
+      helper.triggerUIFromToolbar();
+
+      // There are two iframes in the test page. One iframe is nested in the
+      // other so we SpecialPowers.spawn into the iframes to get the
+      // dimension/position of the elements within each iframe.
+      let elementDimensions = await SpecialPowers.spawn(
+        browser,
+        [],
+        async () => {
+          let divDims = content.document
+            .querySelector("div")
+            .getBoundingClientRect();
+
+          let iframe = content.document.querySelector("iframe");
+          let iframesDivsDimArr = await SpecialPowers.spawn(
+            iframe,
+            [],
+            async () => {
+              let iframeDivDims = content.document
+                .querySelector("div")
+                .getBoundingClientRect();
+
+              // Element within the first iframe
+              iframeDivDims = {
+                left: iframeDivDims.left + content.window.mozInnerScreenX,
+                top: iframeDivDims.top + content.window.mozInnerScreenY,
+                width: iframeDivDims.width,
+                height: iframeDivDims.height,
+              };
+
+              let nestedIframe = content.document.querySelector("iframe");
+              let nestedIframeDivDims = await SpecialPowers.spawn(
+                nestedIframe,
+                [],
+                async () => {
+                  let secondIframeDivDims = content.document
+                    .querySelector("div")
+                    .getBoundingClientRect();
+
+                  // Element within the nested iframe
+                  secondIframeDivDims = {
+                    left:
+                      secondIframeDivDims.left +
+                      content.document.defaultView.mozInnerScreenX,
+                    top:
+                      secondIframeDivDims.top +
+                      content.document.defaultView.mozInnerScreenY,
+                    width: secondIframeDivDims.width,
+                    height: secondIframeDivDims.height,
+                  };
+
+                  return secondIframeDivDims;
+                }
+              );
+
+              return [iframeDivDims, nestedIframeDivDims];
+            }
+          );
+
+          // Offset each element position for the browser window
+          for (let dims of iframesDivsDimArr) {
+            dims.left -= content.window.mozInnerScreenX;
+            dims.top -= content.window.mozInnerScreenY;
+          }
+
+          return [divDims].concat(iframesDivsDimArr);
+        }
+      );
+
+      info(JSON.stringify(elementDimensions, null, 2));
+
+      for (let el of elementDimensions) {
+        let x = el.left + el.width / 2;
+        let y = el.top + el.height / 2;
+
+        mouse.move(x, y);
+        await helper.waitForHoverElementRect(el.width, el.height);
+        mouse.click(x, y);
+
+        await helper.waitForStateChange("selected");
+
+        let dimensions = await helper.getSelectionRegionDimensions();
+
+        is(
+          dimensions.left,
+          el.left,
+          "The region left position matches the elements left position"
+        );
+        is(
+          dimensions.top,
+          el.top,
+          "The region top position matches the elements top position"
+        );
+        is(
+          dimensions.width,
+          el.width,
+          "The region width matches the elements width"
+        );
+        is(
+          dimensions.height,
+          el.height,
+          "The region height matches the elements height"
+        );
+
+        mouse.click(500, 500);
+        await helper.waitForStateChange("crosshairs");
+      }
+    }
+  );
+});
diff --git a/browser/components/screenshots/tests/browser/browser_overlay_keyboard_test.js b/browser/components/screenshots/tests/browser/browser_overlay_keyboard_test.js
new file mode 100644
index 0000000000..592587a67d
--- /dev/null
+++ b/browser/components/screenshots/tests/browser/browser_overlay_keyboard_test.js
@@ -0,0 +1,748 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+const KEY_TO_EXPECTED_POSITION_ARRAY = [
+  [
+    "ArrowRight",
+    {
+      top: 10,
+      left: 20,
+      bottom: 20,
+      right: 30,
+    },
+  ],
+  [
+    "ArrowDown",
+    {
+      top: 20,
+      left: 20,
+      bottom: 30,
+      right: 30,
+    },
+  ],
+  [
+    "ArrowLeft",
+    {
+      top: 20,
+      left: 10,
+      bottom: 30,
+      right: 20,
+    },
+  ],
+  [
+    "ArrowUp",
+    {
+      top: 10,
+      left: 10,
+      bottom: 20,
+      right: 20,
+    },
+  ],
+  ["ArrowDown", { top: 20, left: 10, bottom: 30, right: 20 }],
+  [
+    "ArrowRight",
+    {
+      top: 20,
+      left: 20,
+      bottom: 30,
+      right: 30,
+    },
+  ],
+  [
+    "ArrowUp",
+    {
+      top: 10,
+      left: 20,
+      bottom: 20,
+      right: 30,
+    },
+  ],
+  [
+    "ArrowLeft",
+    {
+      top: 10,
+      left: 10,
+      bottom: 20,
+      right: 20,
+    },
+  ],
+];
+
+const SHIFT_PLUS_KEY_TO_EXPECTED_POSITION_ARRAY = [
+  [
+    "ArrowRight",
+    {
+      top: 100,
+      left: 200,
+      bottom: 200,
+      right: 300,
+    },
+  ],
+  [
+    "ArrowDown",
+    {
+      top: 200,
+      left: 200,
+      bottom: 300,
+      right: 300,
+    },
+  ],
+  [
+    "ArrowLeft",
+    {
+      top: 200,
+      left: 100,
+      bottom: 300,
+      right: 200,
+    },
+  ],
+  [
+    "ArrowUp",
+    {
+      top: 100,
+      left: 100,
+      bottom: 200,
+      right: 200,
+    },
+  ],
+  ["ArrowDown", { top: 200, left: 100, bottom: 300, right: 200 }],
+  [
+    "ArrowRight",
+    {
+      top: 200,
+      left: 200,
+      bottom: 300,
+      right: 300,
+    },
+  ],
+  [
+    "ArrowUp",
+    {
+      top: 100,
+      left: 200,
+      bottom: 200,
+      right: 300,
+    },
+  ],
+  [
+    "ArrowLeft",
+    {
+      top: 100,
+      left: 100,
+      bottom: 200,
+      right: 200,
+    },
+  ],
+];
+
+/**
+ *
+ */
+add_task(async function test_moveRegionWithKeyboard() {
+  await BrowserTestUtils.withNewTab(
+    {
+      gBrowser,
+      url: TEST_PAGE,
+    },
+    async browser => {
+      let helper = new ScreenshotsHelper(browser);
+
+      let contentInfo = await helper.getContentDimensions();
+      ok(contentInfo, "Got dimensions back from the content");
+
+      helper.triggerUIFromToolbar();
+
+      await helper.waitForOverlay();
+
+      // Because the screenshots state won't go from draggingReady to
+      // dragging until the diagonal distance is 40px, we have to resize
+      // it to get the region to 10px x 10px
+      await helper.dragOverlay(10, 10, 100, 100);
+      mouse.down(100, 100);
+      await helper.assertStateChange("resizing");
+      mouse.move(20, 20);
+      mouse.up(20, 20);
+      await helper.assertStateChange("selected");
+
+      await SpecialPowers.spawn(
+        browser,
+        [KEY_TO_EXPECTED_POSITION_ARRAY],
+        async keyToExpectedPositionArray => {
+          function assertSelectionRegionDimensions(
+            actualDimensions,
+            expectedDimensions
+          ) {
+            is(
+              actualDimensions.top,
+              expectedDimensions.top,
+              "Top dimension is correct"
+            );
+            is(
+              actualDimensions.left,
+              expectedDimensions.left,
+              "Left dimension is correct"
+            );
+            is(
+              actualDimensions.bottom,
+              expectedDimensions.bottom,
+              "Bottom dimension is correct"
+            );
+            is(
+              actualDimensions.right,
+              expectedDimensions.right,
+              "Right dimension is correct"
+            );
+          }
+
+          let screenshotsChild = content.windowGlobalChild.getActor(
+            "ScreenshotsComponent"
+          );
+
+          // Test moving each corner of the region
+          screenshotsChild.overlay.topLeftMover.focus();
+
+          // Check that initial position is correct
+          assertSelectionRegionDimensions(
+            screenshotsChild.overlay.selectionRegion.dimensions,
+            {
+              top: 10,
+              left: 10,
+              bottom: 20,
+              right: 20,
+            }
+          );
+
+          for (let [key, expectedDimensions] of keyToExpectedPositionArray) {
+            EventUtils.synthesizeKey(key, { repeat: 20 }, content);
+            assertSelectionRegionDimensions(
+              screenshotsChild.overlay.selectionRegion.dimensions,
+              expectedDimensions
+            );
+          }
+
+          // Test moving the highlight element
+          screenshotsChild.overlay.highlightEl.focus();
+
+          // Check that initial position is correct
+          assertSelectionRegionDimensions(
+            screenshotsChild.overlay.selectionRegion.dimensions,
+            {
+              top: 10,
+              left: 10,
+              bottom: 20,
+              right: 20,
+            }
+          );
+
+          for (let [key, expectedDimensions] of keyToExpectedPositionArray) {
+            EventUtils.synthesizeKey(key, { repeat: 10 }, content);
+            assertSelectionRegionDimensions(
+              screenshotsChild.overlay.selectionRegion.dimensions,
+              expectedDimensions
+            );
+          }
+        }
+      );
+
+      helper.triggerUIFromToolbar();
+      await helper.waitForOverlayClosed();
+    }
+  );
+});
+
+add_task(async function test_moveRegionWithKeyboardWithShift() {
+  await BrowserTestUtils.withNewTab(
+    {
+      gBrowser,
+      url: TEST_PAGE,
+    },
+    async browser => {
+      let helper = new ScreenshotsHelper(browser);
+
+      let contentInfo = await helper.getContentDimensions();
+      ok(contentInfo, "Got dimensions back from the content");
+
+      helper.triggerUIFromToolbar();
+
+      await helper.waitForOverlay();
+
+      await helper.dragOverlay(100, 100, 200, 200);
+
+      await SpecialPowers.spawn(
+        browser,
+        [SHIFT_PLUS_KEY_TO_EXPECTED_POSITION_ARRAY],
+        async shiftPlusKeyToExpectedPositionArray => {
+          function assertSelectionRegionDimensions(
+            actualDimensions,
+            expectedDimensions
+          ) {
+            is(
+              actualDimensions.top,
+              expectedDimensions.top,
+              "Top dimension is correct"
+            );
+            is(
+              actualDimensions.left,
+              expectedDimensions.left,
+              "Left dimension is correct"
+            );
+            is(
+              actualDimensions.bottom,
+              expectedDimensions.bottom,
+              "Bottom dimension is correct"
+            );
+            is(
+              actualDimensions.right,
+              expectedDimensions.right,
+              "Right dimension is correct"
+            );
+          }
+
+          let screenshotsChild = content.windowGlobalChild.getActor(
+            "ScreenshotsComponent"
+          );
+
+          // Test moving each corner of the region
+          screenshotsChild.overlay.topLeftMover.focus();
+
+          // Check that initial position is correct
+          assertSelectionRegionDimensions(
+            screenshotsChild.overlay.selectionRegion.dimensions,
+            {
+              top: 100,
+              left: 100,
+              bottom: 200,
+              right: 200,
+            }
+          );
+
+          for (let [
+            key,
+            expectedDimensions,
+          ] of shiftPlusKeyToExpectedPositionArray) {
+            EventUtils.synthesizeKey(
+              key,
+              { repeat: 20, shiftKey: true },
+              content
+            );
+            assertSelectionRegionDimensions(
+              screenshotsChild.overlay.selectionRegion.dimensions,
+              expectedDimensions
+            );
+          }
+
+          // Test moving the highlight element
+          screenshotsChild.overlay.highlightEl.focus();
+
+          // Check that initial position is correct
+          assertSelectionRegionDimensions(
+            screenshotsChild.overlay.selectionRegion.dimensions,
+            {
+              top: 100,
+              left: 100,
+              bottom: 200,
+              right: 200,
+            }
+          );
+
+          for (let [
+            key,
+            expectedDimensions,
+          ] of shiftPlusKeyToExpectedPositionArray) {
+            EventUtils.synthesizeKey(
+              key,
+              { repeat: 10, shiftKey: true },
+              content
+            );
+            assertSelectionRegionDimensions(
+              screenshotsChild.overlay.selectionRegion.dimensions,
+              expectedDimensions
+            );
+          }
+        }
+      );
+
+      helper.triggerUIFromToolbar();
+      await helper.waitForOverlayClosed();
+    }
+  );
+});
+
+add_task(async function test_moveRegionWithKeyboardWithAccelKey() {
+  await BrowserTestUtils.withNewTab(
+    {
+      gBrowser,
+      url: TEST_PAGE,
+    },
+    async browser => {
+      let helper = new ScreenshotsHelper(browser);
+
+      await helper.scrollContentWindow(100, 100);
+
+      let contentWindowDimensions = await helper.getContentDimensions();
+      ok(contentWindowDimensions, "Got dimensions back from the content");
+
+      helper.triggerUIFromToolbar();
+
+      await helper.waitForOverlay();
+
+      await helper.dragOverlay(100, 100, 200, 200);
+
+      info("Test moving the the highlight element");
+      await SpecialPowers.spawn(
+        browser,
+        [contentWindowDimensions],
+        async contentDimensions => {
+          function assertSelectionRegionDimensions(
+            actualDimensions,
+            expectedDimensions
+          ) {
+            is(
+              actualDimensions.top,
+              expectedDimensions.top,
+              "Top dimension is correct"
+            );
+            is(
+              actualDimensions.left,
+              expectedDimensions.left,
+              "Left dimension is correct"
+            );
+            is(
+              actualDimensions.bottom,
+              expectedDimensions.bottom,
+              "Bottom dimension is correct"
+            );
+            is(
+              actualDimensions.right,
+              expectedDimensions.right,
+              "Right dimension is correct"
+            );
+          }
+
+          let { scrollX, scrollY, clientHeight, clientWidth } =
+            contentDimensions;
+
+          const HIGHLIGHT_CONTROL_PLUS_KEY_TO_EXPECTED_POSITION_ARRAY = [
+            [
+              "ArrowRight",
+              {
+                top: scrollY,
+                left: scrollX + clientWidth - 100,
+                bottom: scrollY + 100,
+                right: scrollX + clientWidth,
+              },
+            ],
+            [
+              "ArrowDown",
+              {
+                top: scrollY + clientHeight - 100,
+                left: scrollX + clientWidth - 100,
+                bottom: scrollY + clientHeight,
+                right: scrollX + clientWidth,
+              },
+            ],
+            [
+              "ArrowLeft",
+              {
+                top: scrollY + clientHeight - 100,
+                left: scrollX,
+                bottom: scrollY + clientHeight,
+                right: scrollX + 100,
+              },
+            ],
+            [
+              "ArrowUp",
+              {
+                top: scrollY,
+                left: scrollX,
+                bottom: scrollY + 100,
+                right: scrollX + 100,
+              },
+            ],
+            [
+              "ArrowDown",
+              {
+                top: scrollY + clientHeight - 100,
+                left: scrollX,
+                bottom: scrollY + clientHeight,
+                right: scrollX + 100,
+              },
+            ],
+            [
+              "ArrowRight",
+              {
+                top: scrollY + clientHeight - 100,
+                left: scrollX + clientWidth - 100,
+                bottom: scrollY + clientHeight,
+                right: scrollX + clientWidth,
+              },
+            ],
+            [
+              "ArrowUp",
+              {
+                top: scrollY,
+                left: scrollX + clientWidth - 100,
+                bottom: scrollY + 100,
+                right: scrollX + clientWidth,
+              },
+            ],
+            [
+              "ArrowLeft",
+              {
+                top: scrollY,
+                left: scrollX,
+                bottom: scrollY + 100,
+                right: scrollX + 100,
+              },
+            ],
+          ];
+
+          let screenshotsChild = content.windowGlobalChild.getActor(
+            "ScreenshotsComponent"
+          );
+          screenshotsChild.overlay.highlightEl.focus();
+
+          // Move the region around in a clockwise direction
+          // Check that original position is correct
+          assertSelectionRegionDimensions(
+            screenshotsChild.overlay.selectionRegion.dimensions,
+            {
+              top: 100,
+              left: 100,
+              bottom: 200,
+              right: 200,
+            }
+          );
+
+          for (let [
+            key,
+            expectedDimensions,
+          ] of HIGHLIGHT_CONTROL_PLUS_KEY_TO_EXPECTED_POSITION_ARRAY) {
+            EventUtils.synthesizeKey(key, { accelKey: true }, content);
+            assertSelectionRegionDimensions(
+              screenshotsChild.overlay.selectionRegion.dimensions,
+              expectedDimensions
+            );
+          }
+        }
+      );
+
+      mouse.click(300, 300);
+      await helper.assertStateChange("crosshairs");
+
+      await helper.dragOverlay(200, 200, 300, 300);
+
+      info("Test moving the corners clockwise");
+      await SpecialPowers.spawn(
+        browser,
+        [contentWindowDimensions],
+        async contentDimensions => {
+          function assertSelectionRegionDimensions(
+            actualDimensions,
+            expectedDimensions
+          ) {
+            is(
+              actualDimensions.top,
+              expectedDimensions.top,
+              "Top dimension is correct"
+            );
+            is(
+              actualDimensions.left,
+              expectedDimensions.left,
+              "Left dimension is correct"
+            );
+            is(
+              actualDimensions.bottom,
+              expectedDimensions.bottom,
+              "Bottom dimension is correct"
+            );
+            is(
+              actualDimensions.right,
+              expectedDimensions.right,
+              "Right dimension is correct"
+            );
+          }
+
+          let { scrollX, scrollY, clientHeight, clientWidth } =
+            contentDimensions;
+
+          const CONTROL_PLUS_KEY_TO_EXPECTED_POSITION_ARRAY = [
+            [
+              "ArrowRight",
+              {
+                top: scrollY + 100,
+                left: scrollX + 100 + 100,
+                bottom: scrollY + 100 + 100,
+                right: scrollX + clientWidth,
+              },
+            ],
+            [
+              "ArrowDown",
+              {
+                top: scrollY + 100 + 100,
+                left: scrollX + 100 + 100,
+                bottom: scrollY + clientHeight,
+                right: scrollX + clientWidth,
+              },
+            ],
+            [
+              "ArrowLeft",
+              {
+                top: scrollY + 100 + 100,
+                left: scrollX,
+                bottom: scrollY + clientHeight,
+                right: scrollX + 100 + 100,
+              },
+            ],
+            [
+              "ArrowUp",
+              {
+                top: scrollY,
+                left: scrollX,
+                bottom: scrollY + 100 + 100,
+                right: scrollX + 100 + 100,
+              },
+            ],
+          ];
+
+          let screenshotsChild = content.windowGlobalChild.getActor(
+            "ScreenshotsComponent"
+          );
+          screenshotsChild.overlay.topLeftMover.focus();
+
+          // Move the region around in a clockwise direction
+          // Check that original position is correct
+          assertSelectionRegionDimensions(
+            screenshotsChild.overlay.selectionRegion.dimensions,
+            {
+              top: 200,
+              left: 200,
+              bottom: 300,
+              right: 300,
+            }
+          );
+
+          for (let [
+            key,
+            expectedDimensions,
+          ] of CONTROL_PLUS_KEY_TO_EXPECTED_POSITION_ARRAY) {
+            EventUtils.synthesizeKey(key, { accelKey: true }, content);
+            assertSelectionRegionDimensions(
+              screenshotsChild.overlay.selectionRegion.dimensions,
+              expectedDimensions
+            );
+          }
+        }
+      );
+
+      mouse.click(400, 400);
+      await helper.assertStateChange("crosshairs");
+
+      await helper.dragOverlay(200, 200, 300, 300);
+
+      info("Test moving the corners counter clockwise");
+      await SpecialPowers.spawn(
+        browser,
+        [contentWindowDimensions],
+        async contentDimensions => {
+          function assertSelectionRegionDimensions(
+            actualDimensions,
+            expectedDimensions
+          ) {
+            is(
+              actualDimensions.top,
+              expectedDimensions.top,
+              "Top dimension is correct"
+            );
+            is(
+              actualDimensions.left,
+              expectedDimensions.left,
+              "Left dimension is correct"
+            );
+            is(
+              actualDimensions.bottom,
+              expectedDimensions.bottom,
+              "Bottom dimension is correct"
+            );
+            is(
+              actualDimensions.right,
+              expectedDimensions.right,
+              "Right dimension is correct"
+            );
+          }
+
+          let { scrollX, scrollY, clientHeight, clientWidth } =
+            contentDimensions;
+
+          const CONTROL_PLUS_KEY_TO_EXPECTED_POSITION_ARRAY = [
+            [
+              "ArrowDown",
+              {
+                top: scrollY + 100 + 100,
+                left: scrollX + 100,
+                bottom: scrollY + clientHeight,
+                right: scrollX + 100 + 100,
+              },
+            ],
+            [
+              "ArrowRight",
+              {
+                top: scrollY + 100 + 100,
+                left: scrollX + 100 + 100,
+                bottom: scrollY + clientHeight,
+                right: scrollX + clientWidth,
+              },
+            ],
+            [
+              "ArrowUp",
+              {
+                top: scrollY,
+                left: scrollX + 100 + 100,
+                bottom: scrollY + 100 + 100,
+                right: scrollX + clientWidth,
+              },
+            ],
+            [
+              "ArrowLeft",
+              {
+                top: scrollY,
+                left: scrollX,
+                bottom: scrollY + 100 + 100,
+                right: scrollX + 100 + 100,
+              },
+            ],
+          ];
+
+          let screenshotsChild = content.windowGlobalChild.getActor(
+            "ScreenshotsComponent"
+          );
+          screenshotsChild.overlay.topLeftMover.focus();
+
+          // Move the region around in a clockwise direction
+          // Check that original position is correct
+          assertSelectionRegionDimensions(
+            screenshotsChild.overlay.selectionRegion.dimensions,
+            {
+              top: 200,
+              left: 200,
+              bottom: 300,
+              right: 300,
+            }
+          );
+
+          for (let [
+            key,
+            expectedDimensions,
+          ] of CONTROL_PLUS_KEY_TO_EXPECTED_POSITION_ARRAY) {
+            EventUtils.synthesizeKey(key, { accelKey: true }, content);
+            assertSelectionRegionDimensions(
+              screenshotsChild.overlay.selectionRegion.dimensions,
+              expectedDimensions
+            );
+          }
+        }
+      );
+    }
+  );
+});
diff --git a/browser/components/screenshots/tests/browser/browser_screenshots_drag_scroll_test.js b/browser/components/screenshots/tests/browser/browser_screenshots_drag_scroll_test.js
new file mode 100644
index 0000000000..7fdb084ca6
--- /dev/null
+++ b/browser/components/screenshots/tests/browser/browser_screenshots_drag_scroll_test.js
@@ -0,0 +1,465 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+/**
+ * Test that screenshots overlay covers the entire page
+ */
+add_task(async function test_overlayCoversEntirePage() {
+  await BrowserTestUtils.withNewTab(
+    {
+      gBrowser,
+      url: TEST_PAGE,
+    },
+    async browser => {
+      let helper = new ScreenshotsHelper(browser);
+      let contentInfo = await helper.getContentDimensions();
+      info(JSON.stringify(contentInfo, null, 2));
+      ok(contentInfo, "Got dimensions back from the content");
+
+      helper.triggerUIFromToolbar();
+
+      await helper.waitForOverlay();
+      await helper.dragOverlay(10, 10, 500, 500);
+
+      let { scrollWidth, scrollHeight } =
+        await helper.getScreenshotsOverlayDimensions();
+
+      is(
+        scrollWidth,
+        contentInfo.scrollWidth,
+        "The overlay spans the entire width of the page"
+      );
+
+      is(
+        scrollHeight,
+        contentInfo.scrollHeight,
+        "The overlay spans the entire height of the page"
+      );
+    }
+  );
+});
+
+/**
+ * Test dragging screenshots box off top left of screen
+ */
+add_task(async function test_draggingBoxOffTopLeft() {
+  await BrowserTestUtils.withNewTab(
+    {
+      gBrowser,
+      url: TEST_PAGE,
+    },
+    async browser => {
+      let helper = new ScreenshotsHelper(browser);
+
+      let contentInfo = await helper.getContentDimensions();
+      ok(contentInfo, "Got dimensions back from the content");
+
+      helper.triggerUIFromToolbar();
+
+      await helper.waitForOverlay();
+
+      let startX = 10;
+      let startY = 10;
+      let endX = 500;
+      let endY = 500;
+      await helper.dragOverlay(startX, startY, endX, endY);
+
+      mouse.down(
+        startX + Math.floor((endX - startX) / 2),
+        startY + Math.floor((endY - startY) / 2)
+      );
+
+      await helper.assertStateChange("resizing");
+
+      mouse.move(10, 10);
+
+      // We moved the box to the edge of the screen so we need to wait until the box size is updated
+      await helper.waitForSelectionRegionSizeChange(490);
+
+      let dimensions = await helper.getSelectionRegionDimensions();
+
+      is(dimensions.left, 0, "The box x1 position is now 0");
+      is(dimensions.top, 0, "The box y1 position is now 0");
+      is(dimensions.width, 255, "The box width is now 255");
+      is(dimensions.height, 255, "The box height is now 255");
+
+      mouse.move(
+        startX + Math.floor((endX - startX) / 2),
+        startY + Math.floor((endY - startY) / 2)
+      );
+
+      mouse.up(
+        startX + Math.floor((endX - startX) / 2),
+        startY + Math.floor((endY - startY) / 2)
+      );
+
+      // We moved the box off the edge of the screen so we need to wait until the box size is updated
+      await helper.waitForSelectionRegionSizeChange(255);
+
+      dimensions = await helper.getSelectionRegionDimensions();
+
+      is(dimensions.left, 10, "The box x1 position is now 10 again");
+      is(dimensions.top, 10, "The box y1 position is now 10 again");
+      is(dimensions.width, 490, "The box width is now 490 again");
+      is(dimensions.height, 490, "The box height is now 490 again");
+    }
+  );
+});
+
+/**
+ * Test dragging screenshots box off bottom right of screen
+ */
+add_task(async function test_draggingBoxOffBottomRight() {
+  await BrowserTestUtils.withNewTab(
+    {
+      gBrowser,
+      url: TEST_PAGE,
+    },
+    async browser => {
+      let helper = new ScreenshotsHelper(browser);
+
+      let contentInfo = await helper.getContentDimensions();
+      info(JSON.stringify(contentInfo));
+      ok(contentInfo, "Got dimensions back from the content");
+
+      await helper.scrollContentWindow(
+        contentInfo.scrollWidth - contentInfo.clientWidth,
+        contentInfo.scrollHeight - contentInfo.clientHeight
+      );
+
+      helper.triggerUIFromToolbar();
+
+      await helper.waitForOverlay();
+
+      let startX = contentInfo.scrollWidth - 500;
+      let startY = contentInfo.scrollHeight - 500;
+      let endX = contentInfo.scrollWidth - 20;
+      let endY = contentInfo.scrollHeight - 20;
+
+      await helper.dragOverlay(startX, startY, endX, endY);
+
+      // move box off the bottom right of the screen
+      mouse.down(
+        startX + Math.floor((endX - startX) / 2),
+        startY + Math.floor((endY - startY) / 2)
+      );
+      mouse.move(
+        startX + 50 + Math.floor((endX - startX) / 2),
+        startY + 50 + Math.floor((endY - startY) / 2)
+      );
+
+      await helper.assertStateChange("resizing");
+
+      mouse.move(endX, endY);
+
+      // We moved the box to the edge of the screen so we need to wait until the box size is updated
+      await helper.waitForSelectionRegionSizeChange(480);
+
+      let dimensions = await helper.getSelectionRegionDimensions();
+
+      is(dimensions.left, startX + 240, "The box x1 position is now 3748");
+      is(dimensions.top, startY + 240, "The box y1 position is now 3756");
+      is(dimensions.width, 260, "The box width is now 260");
+      is(dimensions.height, 260, "The box height is now 260");
+
+      mouse.move(
+        startX + Math.floor((endX - startX) / 2),
+        startY + Math.floor((endY - startY) / 2)
+      );
+
+      mouse.up(
+        startX + Math.floor((endX - startX) / 2),
+        startY + Math.floor((endY - startY) / 2)
+      );
+
+      // We moved the box off the edge of the screen so we need to wait until the box size is updated
+      await helper.waitForSelectionRegionSizeChange(252);
+
+      dimensions = await helper.getSelectionRegionDimensions();
+
+      is(dimensions.left, startX, "The box x1 position is now 3508 again");
+      is(dimensions.top, startY, "The box y1 position is now 3516 again");
+      is(dimensions.width, 480, "The box width is now 480 again");
+      is(dimensions.height, 480, "The box height is now 480 again");
+    }
+  );
+});
+
+/**
+ * test scrolling while screenshots is open
+ */
+add_task(async function test_scrollingScreenshotsOpen() {
+  await BrowserTestUtils.withNewTab(
+    {
+      gBrowser,
+      url: TEST_PAGE,
+    },
+    async browser => {
+      let helper = new ScreenshotsHelper(browser);
+
+      let contentInfo = await helper.getContentDimensions();
+      info(JSON.stringify(contentInfo));
+      ok(contentInfo, "Got dimensions back from the content");
+
+      helper.triggerUIFromToolbar();
+
+      await helper.waitForOverlay();
+
+      let startX = 10;
+      let startY = 10;
+      let endX = 100;
+      let endY = 100;
+
+      await helper.dragOverlay(startX, startY, endX, endY);
+
+      let scrollX = 1000;
+      let scrollY = 1000;
+
+      await helper.scrollContentWindow(scrollX, scrollY);
+
+      let dimensions = await helper.getSelectionRegionDimensions();
+
+      is(dimensions.left, startX, "The box x1 position is 10");
+      is(dimensions.top, startY, "The box y1 position is 10");
+      is(dimensions.width, endX - startX, "The box width is now 90");
+      is(dimensions.height, endY - startY, "The box height is now 90");
+
+      // reset screenshots box
+      await helper.escapeKeyInContent();
+      await helper.assertStateChange("crosshairs");
+
+      await helper.dragOverlay(
+        scrollX + startX,
+        scrollY + startY,
+        scrollX + endX,
+        scrollY + endY
+      );
+
+      await helper.scrollContentWindow(0, 0);
+
+      dimensions = await helper.getSelectionRegionDimensions();
+
+      is(dimensions.left, scrollX + startX, "The box x1 position is 1010");
+      is(dimensions.top, scrollY + startY, "The box y1 position is 1010");
+      is(dimensions.width, endX - startX, "The box width is now 90");
+      is(dimensions.height, endY - startY, "The box height is now 90");
+
+      // reset screenshots box
+      await helper.escapeKeyInContent();
+      await helper.assertStateChange("crosshairs");
+
+      await helper.dragOverlay(
+        startX,
+        startY,
+        contentInfo.clientWidth - 10,
+        contentInfo.clientHeight - 10
+      );
+
+      await helper.scrollContentWindow(
+        contentInfo.clientWidth - 20,
+        contentInfo.clientHeight - 20
+      );
+
+      mouse.down(contentInfo.clientWidth - 10, contentInfo.clientHeight - 10);
+
+      await helper.assertStateChange("resizing");
+
+      mouse.move(
+        contentInfo.clientWidth * 2 - 30,
+        contentInfo.clientHeight * 2 - 30
+      );
+
+      mouse.up(
+        contentInfo.clientWidth * 2 - 30,
+        contentInfo.clientHeight * 2 - 30
+      );
+
+      await helper.assertStateChange("selected");
+
+      let { left, top, right, bottom, width, height } =
+        await helper.getSelectionRegionDimensions();
+      let { scrollWidth, scrollHeight } =
+        await helper.getScreenshotsOverlayDimensions();
+
+      is(left, startX, "The box left is 10");
+      is(top, startY, "The box top is 10");
+      is(
+        right,
+        contentInfo.clientWidth * 2 - 30,
+        "The box right is 2 x clientWidth - 30"
+      );
+      is(
+        bottom,
+        contentInfo.clientHeight * 2 - 30,
+        "The box right is 2 x clientHeight - 30"
+      );
+      is(
+        width,
+        contentInfo.clientWidth * 2 - 40,
+        "The box right is 2 x clientWidth - 40"
+      );
+      is(
+        height,
+        contentInfo.clientHeight * 2 - 40,
+        "The box right is 2 x clientHeight - 40"
+      );
+      is(
+        scrollWidth,
+        contentInfo.scrollWidth,
+        "The overlay spans the entire width of the page"
+      );
+      is(
+        scrollHeight,
+        contentInfo.scrollHeight,
+        "The overlay spans the entire height of the page"
+      );
+    }
+  );
+});
+
+/**
+ * test scroll if by edge
+ */
+add_task(async function test_scrollIfByEdge() {
+  await BrowserTestUtils.withNewTab(
+    {
+      gBrowser,
+      url: TEST_PAGE,
+    },
+    async browser => {
+      let helper = new ScreenshotsHelper(browser);
+
+      let windowX = 1000;
+      let windowY = 1000;
+
+      await helper.scrollContentWindow(windowX, windowY);
+
+      await TestUtils.waitForTick();
+
+      helper.triggerUIFromToolbar();
+      await helper.waitForOverlay();
+
+      let { scrollX, scrollY } = await helper.getContentDimensions();
+
+      is(scrollX, windowX, "Window x position is 1000");
+      is(scrollY, windowY, "Window y position is 1000");
+
+      let startX = 1100;
+      let startY = 1100;
+      let endX = 1010;
+      let endY = 1010;
+
+      // The window won't scroll if the state is draggingReady so we move to
+      // get into the dragging state and then move again to scroll the window
+      mouse.down(startX, startY);
+      await helper.assertStateChange("draggingReady");
+      mouse.move(1050, 1050);
+      await helper.assertStateChange("dragging");
+      mouse.move(endX, endY);
+      mouse.up(endX, endY);
+      await helper.assertStateChange("selected");
+
+      windowX = 990;
+      windowY = 990;
+      await helper.waitForScrollTo(windowX, windowY);
+
+      ({ scrollX, scrollY } = await helper.getContentDimensions());
+
+      is(scrollX, windowX, "Window x position is 990");
+      is(scrollY, windowY, "Window y position is 990");
+
+      let contentInfo = await helper.getContentDimensions();
+
+      endX = windowX + contentInfo.clientWidth - 10;
+      endY = windowY + contentInfo.clientHeight - 10;
+
+      info(
+        `starting to drag overlay to ${endX}, ${endY} in test\nclientInfo: ${JSON.stringify(
+          contentInfo
+        )}\n`
+      );
+      await helper.dragOverlay(startX, startY, endX, endY, "selected");
+
+      windowX = 1000;
+      windowY = 1000;
+      await helper.waitForScrollTo(windowX, windowY);
+
+      ({ scrollX, scrollY } = await helper.getContentDimensions());
+
+      is(scrollX, windowX, "Window x position is 1000");
+      is(scrollY, windowY, "Window y position is 1000");
+    }
+  );
+});
+
+add_task(async function test_scrollIfByEdgeWithKeyboard() {
+  await BrowserTestUtils.withNewTab(
+    {
+      gBrowser,
+      url: TEST_PAGE,
+    },
+    async browser => {
+      let helper = new ScreenshotsHelper(browser);
+
+      let windowX = 1000;
+      let windowY = 1000;
+
+      await helper.scrollContentWindow(windowX, windowY);
+
+      helper.triggerUIFromToolbar();
+      await helper.waitForOverlay();
+
+      let { scrollX, scrollY, clientWidth, clientHeight } =
+        await helper.getContentDimensions();
+
+      is(scrollX, windowX, "Window x position is 1000");
+      is(scrollY, windowY, "Window y position is 1000");
+
+      await helper.dragOverlay(1020, 1020, 1120, 1120);
+
+      await helper.moveOverlayViaKeyboard("highlight", [
+        { key: "ArrowLeft", options: { shiftKey: true } },
+        { key: "ArrowLeft", options: {} },
+        { key: "ArrowUp", options: { shiftKey: true } },
+        { key: "ArrowUp", options: {} },
+      ]);
+
+      windowX = 989;
+      windowY = 989;
+      await helper.waitForScrollTo(windowX, windowY);
+
+      ({ scrollX, scrollY, clientWidth, clientHeight } =
+        await helper.getContentDimensions());
+
+      is(scrollX, windowX, "Window x position is 989");
+      is(scrollY, windowY, "Window y position is 989");
+
+      mouse.click(1200, 1200);
+      await helper.assertStateChange("crosshairs");
+      await helper.dragOverlay(
+        scrollX + clientWidth - 100 - 20,
+        scrollY + clientHeight - 100 - 20,
+        scrollX + clientWidth - 20,
+        scrollY + clientHeight - 20
+      );
+
+      await helper.moveOverlayViaKeyboard("highlight", [
+        { key: "ArrowRight", options: { shiftKey: true } },
+        { key: "ArrowRight", options: {} },
+        { key: "ArrowDown", options: { shiftKey: true } },
+        { key: "ArrowDown", options: {} },
+      ]);
+
+      windowX = 1000;
+      windowY = 1000;
+      await helper.waitForScrollTo(windowX, windowY);
+
+      ({ scrollX, scrollY } = await helper.getContentDimensions());
+
+      is(scrollX, windowX, "Window x position is 1000");
+      is(scrollY, windowY, "Window y position is 1000");
+    }
+  );
+});
diff --git a/browser/components/screenshots/tests/browser/browser_screenshots_drag_test.js b/browser/components/screenshots/tests/browser/browser_screenshots_drag_test.js
new file mode 100644
index 0000000000..605e0ae75c
--- /dev/null
+++ b/browser/components/screenshots/tests/browser/browser_screenshots_drag_test.js
@@ -0,0 +1,488 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+/**
+ * This function drags to a 490x490 area and copies to the clipboard
+ */
+add_task(async function dragTest() {
+  await BrowserTestUtils.withNewTab(
+    {
+      gBrowser,
+      url: TEST_PAGE,
+    },
+    async browser => {
+      let helper = new ScreenshotsHelper(browser);
+      let contentInfo = await helper.getContentDimensions();
+      ok(contentInfo, "Got dimensions back from the content");
+      let expected = Math.floor(
+        490 * (await getContentDevicePixelRatio(browser))
+      );
+
+      helper.triggerUIFromToolbar();
+
+      await helper.waitForOverlay();
+
+      await helper.dragOverlay(10, 10, 500, 500);
+
+      let clipboardChanged = helper.waitForRawClipboardChange(
+        expected,
+        expected
+      );
+
+      await helper.clickCopyButton();
+
+      info("Waiting for clipboard change");
+      let result = await clipboardChanged;
+
+      info("result: " + JSON.stringify(result, null, 2));
+
+      Assert.equal(
+        result.width,
+        expected,
+        `The copied image from the overlay is ${expected}px in width`
+      );
+      Assert.equal(
+        result.height,
+        expected,
+        `The copied image from the overlay is ${expected}px in height`
+      );
+    }
+  );
+});
+
+/**
+ * This function drags a 1.5 zoomed browser to a 490x490 area and copies to the clipboard
+ */
+add_task(async function dragTest1Point5Zoom() {
+  await BrowserTestUtils.withNewTab(
+    {
+      gBrowser,
+      url: TEST_PAGE,
+    },
+    async browser => {
+      const zoom = 1.5;
+      let helper = new ScreenshotsHelper(browser);
+      helper.zoomBrowser(zoom);
+
+      let contentInfo = await helper.getContentDimensions();
+      ok(contentInfo, "Got dimensions back from the content");
+      let expected = Math.floor(
+        50 * (await getContentDevicePixelRatio(browser))
+      );
+
+      helper.triggerUIFromToolbar();
+
+      await helper.waitForOverlay();
+
+      await helper.dragOverlay(300, 100, 350, 150);
+
+      let clipboardChanged = helper.waitForRawClipboardChange(
+        expected,
+        expected
+      );
+
+      await helper.clickCopyButton();
+
+      info("Waiting for clipboard change");
+      let result = await clipboardChanged;
+
+      result.zoom = zoom;
+      result.devicePixelRatio = window.devicePixelRatio;
+      result.contentDevicePixelRatio = await getContentDevicePixelRatio(
+        browser
+      );
+
+      info("result: " + JSON.stringify(result, null, 2));
+
+      Assert.equal(
+        result.width,
+        expected,
+        `The copied image from the overlay is ${expected}px in width`
+      );
+      Assert.equal(
+        result.height,
+        expected,
+        `The copied image from the overlay is ${expected}px in height`
+      );
+    }
+  );
+});
+
+/**
+ * This function drags an area and clicks elsewhere
+ * on the overlay to go back to the crosshairs state
+ */
+add_task(async function clickOverlayResetState() {
+  await BrowserTestUtils.withNewTab(
+    {
+      gBrowser,
+      url: TEST_PAGE,
+    },
+    async browser => {
+      let helper = new ScreenshotsHelper(browser);
+
+      let contentInfo = await helper.getContentDimensions();
+      ok(contentInfo, "Got dimensions back from the content");
+
+      helper.triggerUIFromToolbar();
+
+      await helper.waitForOverlay();
+
+      await helper.dragOverlay(10, 10, 100, 100);
+
+      // click outside overlay
+      mouse.click(200, 200);
+
+      await helper.assertStateChange("crosshairs");
+    }
+  );
+});
+
+/**
+ * This function drags an area and clicks the
+ * cancel button to restart the overlay
+ */
+add_task(async function overlayCancelButton() {
+  await BrowserTestUtils.withNewTab(
+    {
+      gBrowser,
+      url: TEST_PAGE,
+    },
+    async browser => {
+      let helper = new ScreenshotsHelper(browser);
+
+      let contentInfo = await helper.getContentDimensions();
+      ok(contentInfo, "Got dimensions back from the content");
+
+      helper.triggerUIFromToolbar();
+
+      await helper.waitForOverlay();
+
+      await helper.dragOverlay(10, 10, 300, 300);
+
+      await helper.clickCancelButton();
+
+      await helper.assertStateChange("crosshairs");
+    }
+  );
+});
+
+/**
+ * This function drags a 490x490 area and moves it along the edges
+ * and back to the center to confirm that the original size is preserved
+ */
+add_task(async function preserveBoxSizeWhenMovingOutOfWindowBounds() {
+  await BrowserTestUtils.withNewTab(
+    {
+      gBrowser,
+      url: SHORT_TEST_PAGE,
+    },
+    async browser => {
+      let helper = new ScreenshotsHelper(browser);
+
+      let contentInfo = await helper.getContentDimensions();
+      ok(contentInfo, "Got dimensions back from the content");
+      let expected = Math.floor(
+        490 * (await getContentDevicePixelRatio(browser))
+      );
+
+      helper.triggerUIFromToolbar();
+
+      await helper.waitForOverlay();
+
+      await helper.dragOverlay(10, 10, 500, 500);
+
+      let startX = 10;
+      let startY = 10;
+      let endX = 500;
+      let endY = 500;
+
+      mouse.down(
+        Math.floor((endX - startX) / 2),
+        Math.floor((endY - startY) / 2)
+      );
+
+      await helper.assertStateChange("resizing");
+
+      mouse.move(10, 10);
+
+      mouse.move(contentInfo.clientWidth - 10, contentInfo.clientHeight - 10);
+
+      mouse.up(
+        Math.floor((endX - startX) / 2),
+        Math.floor((endY - startY) / 2)
+      );
+
+      await helper.assertStateChange("selected");
+
+      let clipboardChanged = helper.waitForRawClipboardChange(
+        expected,
+        expected
+      );
+
+      await helper.clickCopyButton();
+
+      info("Waiting for clipboard change");
+      let result = await clipboardChanged;
+
+      info("result: " + JSON.stringify(result, null, 2));
+
+      Assert.equal(
+        result.width,
+        expected,
+        `The copied image from the overlay is ${expected}px in width`
+      );
+      Assert.equal(
+        result.height,
+        expected,
+        `The copied image from the overlay is ${expected}px in height`
+      );
+    }
+  );
+});
+
+/**
+ * This function drags a 490x490 area and resizes it to a 300x300 area
+ *  with the 4 sides of the box
+ */
+add_task(async function resizeAllEdges() {
+  await BrowserTestUtils.withNewTab(
+    {
+      gBrowser,
+      url: TEST_PAGE,
+    },
+    async browser => {
+      let helper = new ScreenshotsHelper(browser);
+
+      let contentInfo = await helper.getContentDimensions();
+      ok(contentInfo, "Got dimensions back from the content");
+      let expected = Math.floor(
+        300 * (await getContentDevicePixelRatio(browser))
+      );
+
+      helper.triggerUIFromToolbar();
+
+      await helper.waitForOverlay();
+
+      await helper.dragOverlay(10, 10, 500, 500);
+
+      let startX = 10;
+      let startY = 10;
+      let endX = 500;
+      let endY = 500;
+
+      let x = Math.floor((endX - startX) / 2);
+
+      // drag top
+      mouse.down(x, 10);
+
+      await helper.assertStateChange("resizing");
+
+      mouse.move(x, 100);
+      mouse.up(x, 100);
+
+      await helper.assertStateChange("selected");
+
+      // drag bottom
+      mouse.down(x, 500);
+
+      await helper.assertStateChange("resizing");
+
+      mouse.move(x, 400);
+      mouse.up(x, 400);
+
+      await helper.assertStateChange("selected");
+
+      // drag right
+      let y = Math.floor((endY - startY) / 2);
+      mouse.down(500, y);
+
+      await helper.assertStateChange("resizing");
+
+      mouse.move(400, y);
+      mouse.up(400, y);
+
+      await helper.assertStateChange("selected");
+
+      // drag left
+      mouse.down(10, y);
+
+      await helper.assertStateChange("resizing");
+
+      mouse.move(100, y);
+      mouse.up(100, y);
+
+      await helper.assertStateChange("selected");
+
+      let clipboardChanged = helper.waitForRawClipboardChange(
+        expected,
+        expected
+      );
+
+      helper.endX = 400;
+      helper.endY = 400;
+
+      await helper.clickCopyButton();
+
+      info("Waiting for clipboard change");
+      let result = await clipboardChanged;
+
+      info("result: " + JSON.stringify(result, null, 2));
+
+      Assert.equal(
+        result.width,
+        expected,
+        `The copied image from the overlay is ${expected}px in width`
+      );
+      Assert.equal(
+        result.height,
+        expected,
+        `The copied image from the overlay is ${expected}px in height`
+      );
+    }
+  );
+});
+
+/**
+ * This function drags a 490x490 area and resizes it to a 300x300 area
+ *  with the 4 corners of the box
+ */
+add_task(async function resizeAllCorners() {
+  await BrowserTestUtils.withNewTab(
+    {
+      gBrowser,
+      url: TEST_PAGE,
+    },
+    async browser => {
+      let helper = new ScreenshotsHelper(browser);
+
+      let contentInfo = await helper.getContentDimensions();
+      ok(contentInfo, "Got dimensions back from the content");
+      let expected = Math.floor(
+        300 * (await getContentDevicePixelRatio(browser))
+      );
+
+      helper.triggerUIFromToolbar();
+
+      await helper.waitForOverlay();
+
+      await helper.dragOverlay(10, 10, 500, 500);
+
+      // drag topright
+      mouse.down(500, 10);
+
+      await helper.assertStateChange("resizing");
+
+      mouse.move(450, 50);
+      mouse.up(450, 50);
+
+      await helper.assertStateChange("selected");
+
+      // drag bottomright
+      mouse.down(450, 500);
+
+      await helper.assertStateChange("resizing");
+
+      mouse.move(400, 450);
+      mouse.up(400, 450);
+
+      await helper.assertStateChange("selected");
+
+      // drag bottomleft
+      mouse.down(10, 450);
+
+      await helper.assertStateChange("resizing");
+
+      mouse.move(50, 400);
+      mouse.up(50, 400);
+
+      await helper.assertStateChange("selected");
+
+      // drag topleft
+      mouse.down(50, 50);
+
+      await helper.assertStateChange("resizing");
+
+      mouse.move(100, 100);
+      mouse.up(100, 100);
+
+      await helper.assertStateChange("selected");
+
+      let clipboardChanged = helper.waitForRawClipboardChange(
+        expected,
+        expected
+      );
+
+      helper.endX = 400;
+      helper.endY = 400;
+
+      await helper.clickCopyButton();
+
+      info("Waiting for clipboard change");
+      let result = await clipboardChanged;
+
+      info("result: " + JSON.stringify(result, null, 2));
+
+      Assert.equal(
+        result.width,
+        expected,
+        `The copied image from the overlay is ${expected}px in width`
+      );
+      Assert.equal(
+        result.height,
+        expected,
+        `The copied image from the overlay is ${expected}px in height`
+      );
+    }
+  );
+});
+
+/**
+ * This function tests clicking the overlay with the different mouse buttons
+ */
+add_task(async function test_otherMouseButtons() {
+  await BrowserTestUtils.withNewTab(
+    {
+      gBrowser,
+      url: TEST_PAGE,
+    },
+    async browser => {
+      let helper = new ScreenshotsHelper(browser);
+      helper.triggerUIFromToolbar();
+
+      await helper.waitForOverlay();
+
+      await helper.dragOverlay(10, 10, 100, 100);
+
+      // click outside overlay
+      mouse.click(200, 200, { button: 1 });
+      mouse.click(200, 200, { button: 2 });
+
+      await TestUtils.waitForTick();
+
+      await helper.assertStateChange("selected");
+
+      mouse.click(200, 200);
+
+      await helper.assertStateChange("crosshairs");
+
+      mouse.down(10, 10, { button: 1 });
+      mouse.move(100, 100, { button: 1 });
+      mouse.up(100, 100, { button: 1 });
+
+      await TestUtils.waitForTick();
+
+      await helper.assertStateChange("crosshairs");
+
+      mouse.down(10, 10, { button: 2 });
+      mouse.move(100, 100, { button: 2 });
+      mouse.up(100, 100, { button: 2 });
+
+      await TestUtils.waitForTick();
+
+      await helper.assertStateChange("crosshairs");
+    }
+  );
+});
diff --git a/browser/components/screenshots/tests/browser/browser_screenshots_focus_test.js b/browser/components/screenshots/tests/browser/browser_screenshots_focus_test.js
new file mode 100644
index 0000000000..367f62205e
--- /dev/null
+++ b/browser/components/screenshots/tests/browser/browser_screenshots_focus_test.js
@@ -0,0 +1,384 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+const SCREENSHOTS_EVENTS = [
+  { category: "screenshots", method: "started", object: "toolbar_button" },
+  { category: "screenshots", method: "canceled", object: "escape" },
+];
+
+const SCREENSHOTS_LAST_SCREENSHOT_METHOD_PREF =
+  "screenshots.browser.component.last-screenshot-method";
+const SCREENSHOTS_LAST_SAVED_METHOD_PREF =
+  "screenshots.browser.component.last-saved-method";
+
+async function restoreFocusOnEscape(initialFocusElem, helper) {
+  info(
+    `restoreFocusOnEscape, focusedElement: ${Services.focus.focusedElement.localName}#${Services.focus.focusedElement.id}`
+  );
+  is(
+    window,
+    BrowserWindowTracker.getTopWindow(),
+    "Our window is the top window"
+  );
+
+  let gotFocus;
+  if (Services.focus.focusedElement !== initialFocusElem) {
+    gotFocus = BrowserTestUtils.waitForEvent(initialFocusElem, "focus");
+    await SimpleTest.promiseFocus(initialFocusElem.ownerGlobal);
+    Services.focus.setFocus(initialFocusElem, Services.focus.FLAG_BYKEY);
+    info(
+      `Waiting to place focus on initialFocusElem: ${initialFocusElem.localName}#${initialFocusElem.id}`
+    );
+    await gotFocus;
+  }
+  is(
+    Services.focus.focusedElement,
+    initialFocusElem,
+    `The initial element #${initialFocusElem.id} has focus`
+  );
+
+  helper.assertPanelNotVisible();
+  // open Screenshots with the keyboard shortcut
+  info(
+    "Triggering screenshots UI with the ctrl+shift+s and waiting for the panel"
+  );
+  EventUtils.synthesizeKey("s", { shiftKey: true, accelKey: true });
+
+  let button = await helper.getPanelButton(".visible-page");
+  info("Panel is now visible, got button: " + button.className);
+  info(
+    `focusedElement: ${Services.focus.focusedElement.localName}.${Services.focus.focusedElement.className}`
+  );
+
+  await BrowserTestUtils.waitForCondition(async () => {
+    return button.getRootNode().activeElement === button;
+  }, "The first button in the panel should have focus");
+
+  info(
+    "Sending Escape to dismiss the screenshots UI and for the panel to be closed"
+  );
+
+  let exitObserved = TestUtils.topicObserved("screenshots-exit");
+  EventUtils.synthesizeKey("KEY_Escape");
+  await helper.waitForPanelClosed();
+  await exitObserved;
+  info("Waiting for the initialFocusElem to be the focusedElement");
+  await BrowserTestUtils.waitForCondition(async () => {
+    return Services.focus.focusedElement === initialFocusElem;
+  }, "The initially focused element should have focus");
+
+  info(
+    `Screenshots did exit, focusedElement: ${Services.focus.focusedElement.localName}#${Services.focus.focusedElement.id}`
+  );
+  helper.assertPanelNotVisible();
+}
+
+add_task(async function testPanelFocused() {
+  await BrowserTestUtils.withNewTab(
+    {
+      gBrowser,
+      url: TEST_PAGE,
+    },
+    async browser => {
+      await clearAllTelemetryEvents();
+      let helper = new ScreenshotsHelper(browser);
+
+      info("Opening Screenshots and waiting for the panel");
+      helper.triggerUIFromToolbar();
+
+      let button = await helper.getPanelButton(".visible-page");
+      info("Panel is now visible, got button: " + button.className);
+      info(
+        `focusedElement: ${Services.focus.focusedElement.localName}.${Services.focus.focusedElement.className}`
+      );
+
+      info("Waiting for the button to be the activeElement");
+      await BrowserTestUtils.waitForCondition(() => {
+        return button.getRootNode().activeElement === button;
+      }, "The first button in the panel should have focus");
+
+      info("Sending Escape to close Screenshots");
+      let exitObserved = TestUtils.topicObserved("screenshots-exit");
+      EventUtils.synthesizeKey("KEY_Escape");
+
+      info("waiting for the panel to be closed");
+      await helper.waitForPanelClosed();
+      info("waiting for the overlay to be closed");
+      await helper.waitForOverlayClosed();
+      await exitObserved;
+
+      info("Checking telemetry");
+      await assertScreenshotsEvents(SCREENSHOTS_EVENTS);
+      helper.assertPanelNotVisible();
+    }
+  );
+});
+
+add_task(async function testRestoreFocusToChromeOnEscape() {
+  for (let focusSelector of [
+    "#urlbar-input", // A focusable HTML chrome element
+    "tab[selected='true']", // The selected tab element
+  ]) {
+    await BrowserTestUtils.withNewTab(
+      {
+        gBrowser,
+        url: TEST_PAGE,
+      },
+      async browser => {
+        let helper = new ScreenshotsHelper(browser);
+        helper.assertPanelNotVisible();
+        let initialFocusElem = document.querySelector(focusSelector);
+        await SimpleTest.promiseFocus(window);
+        await restoreFocusOnEscape(initialFocusElem, helper);
+      }
+    );
+  }
+});
+
+add_task(async function testRestoreFocusToToolbarbuttonOnEscape() {
+  const focusId = "PanelUI-menu-button"; // a toolbarbutton
+  await BrowserTestUtils.withNewTab(
+    {
+      gBrowser,
+      url: TEST_PAGE,
+    },
+    async browser => {
+      let helper = new ScreenshotsHelper(browser);
+      helper.assertPanelNotVisible();
+      let initialFocusElem = document.getElementById(focusId);
+      await SimpleTest.promiseFocus(window);
+      await restoreFocusOnEscape(initialFocusElem, helper);
+    }
+  );
+}).skip(); // Bug 1867687
+
+add_task(async function testRestoreFocusToContentOnEscape() {
+  await BrowserTestUtils.withNewTab(
+    {
+      gBrowser,
+      url: 'data:text/html;charset=utf-8,%3Cinput type%3D"text" id%3D"field"%3E',
+    },
+    async browser => {
+      let helper = new ScreenshotsHelper(browser);
+      await SimpleTest.promiseFocus(browser);
+      await BrowserTestUtils.synthesizeMouse("#field", 2, 2, {}, browser);
+
+      let initialFocusElem = Services.focus.focusedElement;
+      await restoreFocusOnEscape(initialFocusElem, helper);
+
+      is(
+        initialFocusElem,
+        document.activeElement,
+        "The browser element has focus"
+      );
+      let focusId = await SpecialPowers.spawn(browser, [], () => {
+        return content.document.activeElement.id;
+      });
+      is(focusId, "field", "The button in the content document has focus");
+    }
+  );
+});
+
+add_task(async function test_focusLastUsedMethod() {
+  await SpecialPowers.pushPrefEnv({
+    set: [
+      [SCREENSHOTS_LAST_SCREENSHOT_METHOD_PREF, ""],
+      [SCREENSHOTS_LAST_SAVED_METHOD_PREF, ""],
+      ["browser.download.useDownloadDir", true],
+    ],
+  });
+
+  let publicDownloads = await Downloads.getList(Downloads.PUBLIC);
+  // First ensure we catch the download finishing.
+  let downloadFinishedPromise = new Promise(resolve => {
+    publicDownloads.addView({
+      onDownloadChanged(download) {
+        info("Download changed!");
+        if (download.succeeded || download.error) {
+          info("Download succeeded or errored");
+          publicDownloads.removeView(this);
+          resolve(download);
+        }
+      },
+    });
+  });
+
+  await BrowserTestUtils.withNewTab(
+    {
+      gBrowser,
+      url: SHORT_TEST_PAGE,
+    },
+    async browser => {
+      let helper = new ScreenshotsHelper(browser);
+      helper.triggerUIFromToolbar();
+      await helper.waitForOverlay();
+
+      let expectedFocusedButton = await helper.getPanelButton(".visible-page");
+
+      await BrowserTestUtils.waitForCondition(() => {
+        return (
+          expectedFocusedButton.getRootNode().activeElement ===
+          expectedFocusedButton
+        );
+      }, "The visible button in the panel should have focus");
+
+      is(
+        Services.focus.focusedElement,
+        expectedFocusedButton,
+        "The visible button in the panel should have focus"
+      );
+
+      let screenshotReady = TestUtils.topicObserved(
+        "screenshots-preview-ready"
+      );
+      let fullpageButton = await helper.getPanelButton(".full-page");
+      fullpageButton.click();
+      await screenshotReady;
+
+      let dialog = helper.getDialog();
+      let retryButton = dialog._frame.contentDocument.getElementById("retry");
+      retryButton.click();
+
+      await helper.waitForOverlay();
+
+      expectedFocusedButton = await helper.getPanelButton(".full-page");
+
+      await BrowserTestUtils.waitForCondition(() => {
+        return (
+          expectedFocusedButton.getRootNode().activeElement ===
+          expectedFocusedButton
+        );
+      }, "The full page button in the panel should have focus");
+
+      is(
+        Services.focus.focusedElement,
+        expectedFocusedButton,
+        "The full button in the panel should have focus"
+      );
+
+      screenshotReady = TestUtils.topicObserved("screenshots-preview-ready");
+      let visiblepageButton = await helper.getPanelButton(".visible-page");
+      visiblepageButton.click();
+      await screenshotReady;
+
+      dialog = helper.getDialog();
+      retryButton = dialog._frame.contentDocument.getElementById("retry");
+      retryButton.click();
+
+      await helper.waitForOverlay();
+
+      expectedFocusedButton = await helper.getPanelButton(".visible-page");
+
+      await BrowserTestUtils.waitForCondition(() => {
+        return (
+          expectedFocusedButton.getRootNode().activeElement ===
+          expectedFocusedButton
+        );
+      }, "The visible button in the panel should have focus");
+
+      is(
+        Services.focus.focusedElement,
+        expectedFocusedButton,
+        "The visible button in the panel should have focus"
+      );
+
+      screenshotReady = TestUtils.topicObserved("screenshots-preview-ready");
+      expectedFocusedButton.click();
+      await screenshotReady;
+
+      dialog = helper.getDialog();
+
+      expectedFocusedButton =
+        dialog._frame.contentDocument.getElementById("download");
+
+      await BrowserTestUtils.waitForCondition(() => {
+        return (
+          expectedFocusedButton.getRootNode().activeElement ===
+          expectedFocusedButton
+        );
+      }, "The download button in the preview dialog should have focus");
+
+      is(
+        Services.focus.focusedElement,
+        expectedFocusedButton,
+        "The download button in the preview dialog should have focus"
+      );
+
+      let screenshotExit = TestUtils.topicObserved("screenshots-exit");
+      let copyButton = dialog._frame.contentDocument.getElementById("copy");
+      copyButton.click();
+      await screenshotExit;
+
+      helper.triggerUIFromToolbar();
+      await helper.waitForOverlay();
+
+      let visibleButton = await helper.getPanelButton(".visible-page");
+
+      screenshotReady = TestUtils.topicObserved("screenshots-preview-ready");
+      visibleButton.click();
+      await screenshotReady;
+
+      dialog = helper.getDialog();
+
+      expectedFocusedButton =
+        dialog._frame.contentDocument.getElementById("copy");
+
+      await BrowserTestUtils.waitForCondition(() => {
+        return (
+          expectedFocusedButton.getRootNode().activeElement ===
+          expectedFocusedButton
+        );
+      }, "The copy button in the preview dialog should have focus");
+
+      is(
+        Services.focus.focusedElement,
+        expectedFocusedButton,
+        "The copy button in the preview dialog should have focus"
+      );
+
+      screenshotExit = TestUtils.topicObserved("screenshots-exit");
+      let downloadButton =
+        dialog._frame.contentDocument.getElementById("download");
+      downloadButton.click();
+
+      await Promise.all([screenshotExit, downloadFinishedPromise]);
+
+      await publicDownloads.removeFinished();
+
+      helper.triggerUIFromToolbar();
+      await helper.waitForOverlay();
+
+      visibleButton = await helper.getPanelButton(".visible-page");
+
+      screenshotReady = TestUtils.topicObserved("screenshots-preview-ready");
+      visibleButton.click();
+      await screenshotReady;
+
+      dialog = helper.getDialog();
+
+      expectedFocusedButton =
+        dialog._frame.contentDocument.getElementById("download");
+
+      await BrowserTestUtils.waitForCondition(() => {
+        return (
+          expectedFocusedButton.getRootNode().activeElement ===
+          expectedFocusedButton
+        );
+      }, "The download button in the preview dialog should have focus");
+
+      is(
+        Services.focus.focusedElement,
+        expectedFocusedButton,
+        "The download button in the preview dialog should have focus"
+      );
+
+      screenshotExit = TestUtils.topicObserved("screenshots-exit");
+      helper.triggerUIFromToolbar();
+      await screenshotExit;
+    }
+  );
+
+  await SpecialPowers.popPrefEnv();
+});
diff --git a/browser/components/screenshots/tests/browser/browser_screenshots_overlay_panel_sync.js b/browser/components/screenshots/tests/browser/browser_screenshots_overlay_panel_sync.js
new file mode 100644
index 0000000000..0f54255dc0
--- /dev/null
+++ b/browser/components/screenshots/tests/browser/browser_screenshots_overlay_panel_sync.js
@@ -0,0 +1,74 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+async function waitOnTabSwitch() {
+  // eslint-disable-next-line mozilla/no-arbitrary-setTimeout
+  await new Promise(r => setTimeout(r, 300));
+}
+
+add_task(async function test_overlay_and_panel_state() {
+  let tab1 = await BrowserTestUtils.openNewForegroundTab(gBrowser, TEST_PAGE);
+
+  let screenshotsTab = await BrowserTestUtils.openNewForegroundTab(
+    gBrowser,
+    TEST_PAGE
+  );
+  let browser = screenshotsTab.linkedBrowser;
+
+  let helper = new ScreenshotsHelper(browser);
+
+  helper.triggerUIFromToolbar();
+
+  await helper.waitForOverlay();
+
+  helper.assertPanelVisible();
+
+  await helper.dragOverlay(10, 10, 500, 500);
+
+  await helper.assertStateChange("selected");
+
+  helper.assertPanelNotVisible();
+
+  mouse.click(600, 600);
+
+  await helper.assertStateChange("crosshairs");
+
+  await helper.waitForOverlay();
+
+  helper.assertPanelVisible();
+
+  await BrowserTestUtils.switchTab(gBrowser, tab1);
+  await BrowserTestUtils.switchTab(gBrowser, screenshotsTab);
+
+  await helper.waitForOverlayClosed();
+
+  Assert.ok(!(await helper.isOverlayInitialized()), "Overlay is closed");
+  helper.assertPanelNotVisible();
+
+  helper.triggerUIFromToolbar();
+
+  await helper.waitForOverlay();
+
+  helper.assertPanelVisible();
+
+  await helper.dragOverlay(10, 10, 500, 500);
+
+  await helper.assertStateChange("selected");
+
+  await BrowserTestUtils.switchTab(gBrowser, tab1);
+  await BrowserTestUtils.switchTab(gBrowser, screenshotsTab);
+
+  Assert.ok(await helper.isOverlayInitialized(), "Overlay is open");
+  helper.assertPanelNotVisible();
+
+  helper.triggerUIFromToolbar();
+  await helper.waitForOverlayClosed();
+
+  Assert.ok(!(await helper.isOverlayInitialized()), "Overlay is closed");
+  helper.assertPanelNotVisible();
+
+  gBrowser.removeTab(tab1);
+  gBrowser.removeTab(screenshotsTab);
+});
diff --git a/browser/components/screenshots/tests/browser/browser_screenshots_page_unload.js b/browser/components/screenshots/tests/browser/browser_screenshots_page_unload.js
new file mode 100644
index 0000000000..fbb5788a5a
--- /dev/null
+++ b/browser/components/screenshots/tests/browser/browser_screenshots_page_unload.js
@@ -0,0 +1,42 @@
+/* Any copyright is dedicated to the Public Domain.
+  http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+const SCREENSHOTS_EVENTS = [
+  { category: "screenshots", method: "started", object: "toolbar_button" },
+  { category: "screenshots", method: "canceled", object: "navigation" },
+];
+
+add_task(async function test() {
+  await BrowserTestUtils.withNewTab(
+    {
+      gBrowser,
+      url: SHORT_TEST_PAGE,
+    },
+    async browser => {
+      await clearAllTelemetryEvents();
+      await SpecialPowers.spawn(browser, [SHORT_TEST_PAGE], url => {
+        let a = content.document.createElement("a");
+        a.id = "clickMe";
+        a.href = url;
+        a.textContent = "Click me to unload page";
+        content.document.querySelector("body").appendChild(a);
+      });
+
+      let helper = new ScreenshotsHelper(browser);
+
+      // click toolbar button so panel shows
+      helper.triggerUIFromToolbar();
+      await helper.waitForOverlay();
+
+      await SpecialPowers.spawn(browser, [], () => {
+        content.document.querySelector("#clickMe").click();
+      });
+
+      await helper.waitForOverlayClosed();
+
+      await assertScreenshotsEvents(SCREENSHOTS_EVENTS);
+    }
+  );
+});
diff --git a/browser/components/screenshots/tests/browser/browser_screenshots_short_page_test.js b/browser/components/screenshots/tests/browser/browser_screenshots_short_page_test.js
new file mode 100644
index 0000000000..bebc70e915
--- /dev/null
+++ b/browser/components/screenshots/tests/browser/browser_screenshots_short_page_test.js
@@ -0,0 +1,123 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+/**
+ * This test ensures the overlay is covering the entire window event thought
+ * the body is smaller than the viewport
+ */
+add_task(async function test_overlay() {
+  await BrowserTestUtils.withNewTab(
+    {
+      gBrowser,
+      url: SHORT_TEST_PAGE,
+    },
+    async browser => {
+      let helper = new ScreenshotsHelper(browser);
+      let contentInfo = await helper.getContentDimensions();
+      ok(contentInfo, "Got dimensions back from the content");
+
+      helper.triggerUIFromToolbar();
+
+      await helper.waitForOverlay();
+
+      await helper.dragOverlay(10, 10, 500, 500);
+
+      let { scrollWidth, scrollHeight } =
+        await helper.getScreenshotsOverlayDimensions();
+      Assert.equal(
+        scrollWidth,
+        contentInfo.clientWidth,
+        "The overlay spans the width of the window"
+      );
+
+      Assert.equal(
+        scrollHeight,
+        contentInfo.clientHeight,
+        "The overlay spans the height of the window"
+      );
+    }
+  );
+});
+
+add_task(async function test_window_resize() {
+  await BrowserTestUtils.withNewTab(
+    {
+      gBrowser,
+      url: SHORT_TEST_PAGE,
+    },
+    async browser => {
+      let helper = new ScreenshotsHelper(browser);
+      let contentInfo = await helper.getContentDimensions();
+      ok(contentInfo, "Got dimensions back from the content");
+
+      const originalWindowWidth = window.outerWidth;
+      const originalWindowHeight = window.outerHeight;
+
+      const BIG_WINDOW_SIZE = 920;
+      const SMALL_WINDOW_SIZE = 620;
+
+      await helper.resizeContentWindow(SMALL_WINDOW_SIZE, SMALL_WINDOW_SIZE);
+
+      helper.triggerUIFromToolbar();
+      await helper.waitForOverlay();
+      await helper.dragOverlay(10, 10, 100, 100);
+
+      let dimensions = await helper.getScreenshotsOverlayDimensions();
+      let oldWidth = dimensions.scrollWidth;
+      let oldHeight = dimensions.scrollHeight;
+
+      await helper.resizeContentWindow(BIG_WINDOW_SIZE, BIG_WINDOW_SIZE);
+      await helper.waitForSelectionLayerDimensionChange(oldWidth, oldHeight);
+
+      contentInfo = await helper.getContentDimensions();
+      dimensions = await helper.getScreenshotsOverlayDimensions();
+      Assert.equal(
+        dimensions.scrollWidth,
+        contentInfo.clientWidth,
+        "The overlay spans the width of the window"
+      );
+      Assert.equal(
+        dimensions.scrollHeight,
+        contentInfo.clientHeight,
+        "The overlay spans the height of the window"
+      );
+
+      oldWidth = dimensions.scrollWidth;
+      oldHeight = dimensions.scrollHeight;
+
+      await helper.resizeContentWindow(SMALL_WINDOW_SIZE, SMALL_WINDOW_SIZE);
+      await helper.waitForSelectionLayerDimensionChange(oldWidth, oldHeight);
+
+      contentInfo = await helper.getContentDimensions();
+      dimensions = await helper.getScreenshotsOverlayDimensions();
+      Assert.equal(
+        dimensions.scrollWidth,
+        contentInfo.clientWidth,
+        "The overlay spans the width of the window"
+      );
+      Assert.equal(
+        dimensions.scrollHeight,
+        contentInfo.clientHeight,
+        "The overlay spans the height of the window"
+      );
+
+      Assert.less(
+        dimensions.scrollWidth,
+        BIG_WINDOW_SIZE,
+        "Screenshots overlay is smaller than the big window width"
+      );
+      Assert.less(
+        dimensions.scrollHeight,
+        BIG_WINDOW_SIZE,
+        "Screenshots overlay is smaller than the big window height"
+      );
+
+      await helper.resizeContentWindow(
+        originalWindowWidth,
+        originalWindowHeight
+      );
+    }
+  );
+});
diff --git a/browser/components/screenshots/tests/browser/browser_screenshots_telemetry_tests.js b/browser/components/screenshots/tests/browser/browser_screenshots_telemetry_tests.js
new file mode 100644
index 0000000000..782ffa3fd3
--- /dev/null
+++ b/browser/components/screenshots/tests/browser/browser_screenshots_telemetry_tests.js
@@ -0,0 +1,466 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+const STARTED_AND_CANCELED_EVENTS = [
+  { category: "screenshots", method: "started", object: "toolbar_button" },
+  { category: "screenshots", method: "canceled", object: "toolbar_button" },
+  { category: "screenshots", method: "started", object: "shortcut" },
+  { category: "screenshots", method: "canceled", object: "shortcut" },
+  { category: "screenshots", method: "started", object: "context_menu" },
+  { category: "screenshots", method: "canceled", object: "context_menu" },
+  { category: "screenshots", method: "started", object: "quick_actions" },
+  { category: "screenshots", method: "canceled", object: "quick_actions" },
+];
+
+const STARTED_RETRY_EVENTS = [
+  { category: "screenshots", method: "started", object: "toolbar_button" },
+  { category: "screenshots", method: "selected", object: "visible" },
+  { category: "screenshots", method: "started", object: "preview_retry" },
+];
+
+const CANCEL_EVENTS = [
+  { category: "screenshots", method: "started", object: "toolbar_button" },
+  { category: "screenshots", method: "selected", object: "full_page" },
+  { category: "screenshots", method: "canceled", object: "preview_cancel" },
+  { category: "screenshots", method: "started", object: "toolbar_button" },
+  { category: "screenshots", method: "canceled", object: "overlay_cancel" },
+];
+
+const COPY_EVENTS = [
+  { category: "screenshots", method: "started", object: "toolbar_button" },
+  { category: "screenshots", method: "selected", object: "visible" },
+  { category: "screenshots", method: "copy", object: "preview_copy" },
+  { category: "screenshots", method: "started", object: "toolbar_button" },
+  { category: "screenshots", method: "copy", object: "overlay_copy" },
+];
+
+const CONTENT_EVENTS = [
+  { category: "screenshots", method: "selected", object: "region_selection" },
+  { category: "screenshots", method: "selected", object: "region_selection" },
+  { category: "screenshots", method: "started", object: "overlay_retry" },
+  { category: "screenshots", method: "selected", object: "element" },
+];
+
+const EXTRA_OVERLAY_EVENTS = [
+  { category: "screenshots", method: "started", object: "toolbar_button" },
+  {
+    category: "screenshots",
+    method: "copy",
+    object: "overlay_copy",
+    extra: {
+      element: "1",
+      region: "1",
+      move: "1",
+      resize: "1",
+      fullpage: "0",
+      visible: "0",
+    },
+  },
+];
+
+const EXTRA_EVENTS = [
+  { category: "screenshots", method: "started", object: "toolbar_button" },
+  { category: "screenshots", method: "selected", object: "visible" },
+  { category: "screenshots", method: "started", object: "preview_retry" },
+  { category: "screenshots", method: "selected", object: "full_page" },
+  {
+    category: "screenshots",
+    method: "copy",
+    object: "preview_copy",
+    extra: {
+      element: "0",
+      region: "0",
+      move: "0",
+      resize: "0",
+      fullpage: "1",
+      visible: "1",
+    },
+  },
+];
+
+add_task(async function test_started_and_canceled_events() {
+  await SpecialPowers.pushPrefEnv({
+    set: [
+      ["browser.urlbar.quickactions.enabled", true],
+      ["browser.urlbar.suggest.quickactions", true],
+      ["browser.urlbar.shortcuts.quickactions", true],
+    ],
+  });
+
+  await BrowserTestUtils.withNewTab(
+    {
+      gBrowser,
+      url: SHORT_TEST_PAGE,
+    },
+    async browser => {
+      await clearAllTelemetryEvents();
+      let helper = new ScreenshotsHelper(browser);
+      let screenshotExit;
+
+      helper.triggerUIFromToolbar();
+      await helper.waitForOverlay();
+
+      screenshotExit = TestUtils.topicObserved("screenshots-exit");
+      helper.triggerUIFromToolbar();
+      await helper.waitForOverlayClosed();
+      await screenshotExit;
+
+      EventUtils.synthesizeKey("s", { shiftKey: true, accelKey: true });
+      await helper.waitForOverlay();
+
+      screenshotExit = TestUtils.topicObserved("screenshots-exit");
+      EventUtils.synthesizeKey("s", { shiftKey: true, accelKey: true });
+      await helper.waitForOverlayClosed();
+      await screenshotExit;
+
+      let contextMenu = document.getElementById("contentAreaContextMenu");
+      let popupShownPromise = BrowserTestUtils.waitForEvent(
+        contextMenu,
+        "popupshown"
+      );
+      await BrowserTestUtils.synthesizeMouseAtPoint(
+        50,
+        50,
+        {
+          type: "contextmenu",
+          button: 2,
+        },
+        browser
+      );
+      await popupShownPromise;
+
+      contextMenu.activateItem(
+        contextMenu.querySelector("#context-take-screenshot")
+      );
+      await helper.waitForOverlay();
+
+      popupShownPromise = BrowserTestUtils.waitForEvent(
+        contextMenu,
+        "popupshown"
+      );
+      await BrowserTestUtils.synthesizeMouseAtPoint(
+        50,
+        50,
+        {
+          type: "contextmenu",
+          button: 2,
+        },
+        browser
+      );
+      await popupShownPromise;
+
+      screenshotExit = TestUtils.topicObserved("screenshots-exit");
+      contextMenu.activateItem(
+        contextMenu.querySelector("#context-take-screenshot")
+      );
+      await helper.waitForOverlayClosed();
+      await screenshotExit;
+
+      await UrlbarTestUtils.promiseAutocompleteResultPopup({
+        window,
+        value: "screenshot",
+        waitForFocus: SimpleTest.waitForFocus,
+      });
+      let { result } = await UrlbarTestUtils.getDetailsOfResultAt(window, 1);
+      Assert.equal(result.type, UrlbarUtils.RESULT_TYPE.DYNAMIC);
+      Assert.equal(result.providerName, "quickactions");
+
+      info("Trigger the screenshot mode");
+      EventUtils.synthesizeKey("KEY_ArrowDown", {}, window);
+      EventUtils.synthesizeKey("KEY_Enter", {}, window);
+      await helper.waitForOverlay();
+
+      await UrlbarTestUtils.promiseAutocompleteResultPopup({
+        window,
+        value: "screenshot",
+        waitForFocus: SimpleTest.waitForFocus,
+      });
+      ({ result } = await UrlbarTestUtils.getDetailsOfResultAt(window, 1));
+      Assert.equal(result.type, UrlbarUtils.RESULT_TYPE.DYNAMIC);
+      Assert.equal(result.providerName, "quickactions");
+
+      info("Trigger the screenshot mode");
+      screenshotExit = TestUtils.topicObserved("screenshots-exit");
+      EventUtils.synthesizeKey("KEY_ArrowDown", {}, window);
+      EventUtils.synthesizeKey("KEY_Enter", {}, window);
+      await helper.waitForOverlayClosed();
+      await screenshotExit;
+
+      await assertScreenshotsEvents(STARTED_AND_CANCELED_EVENTS);
+    }
+  );
+});
+
+add_task(async function test_started_retry() {
+  await BrowserTestUtils.withNewTab(
+    {
+      gBrowser,
+      url: TEST_PAGE,
+    },
+    async browser => {
+      await clearAllTelemetryEvents();
+      let helper = new ScreenshotsHelper(browser);
+
+      helper.triggerUIFromToolbar();
+      await helper.waitForOverlay();
+
+      let panel = await helper.waitForPanel();
+
+      let screenshotReady = TestUtils.topicObserved(
+        "screenshots-preview-ready"
+      );
+
+      // click the visible page button in panel
+      let visiblePageButton = panel
+        .querySelector("screenshots-buttons")
+        .shadowRoot.querySelector(".visible-page");
+      visiblePageButton.click();
+      await screenshotReady;
+
+      let dialog = helper.getDialog();
+      let retryButton = dialog._frame.contentDocument.getElementById("retry");
+      ok(retryButton, "Got the retry button");
+      retryButton.click();
+
+      await helper.waitForOverlay();
+
+      await assertScreenshotsEvents(STARTED_RETRY_EVENTS);
+    }
+  );
+});
+
+add_task(async function test_canceled() {
+  await BrowserTestUtils.withNewTab(
+    {
+      gBrowser,
+      url: TEST_PAGE,
+    },
+    async browser => {
+      await clearAllTelemetryEvents();
+      let helper = new ScreenshotsHelper(browser);
+
+      helper.triggerUIFromToolbar();
+      await helper.waitForOverlay();
+
+      let panel = await helper.waitForPanel();
+
+      let screenshotReady = TestUtils.topicObserved(
+        "screenshots-preview-ready"
+      );
+
+      // click the full page button in panel
+      let fullPageButton = panel
+        .querySelector("screenshots-buttons")
+        .shadowRoot.querySelector(".full-page");
+      fullPageButton.click();
+      await screenshotReady;
+
+      let dialog = helper.getDialog();
+      let cancelButton = dialog._frame.contentDocument.getElementById("cancel");
+      ok(cancelButton, "Got the cancel button");
+
+      let screenshotExit = TestUtils.topicObserved("screenshots-exit");
+      cancelButton.click();
+
+      await helper.waitForOverlayClosed();
+      await screenshotExit;
+
+      helper.triggerUIFromToolbar();
+      await helper.waitForOverlay();
+
+      screenshotExit = TestUtils.topicObserved("screenshots-exit");
+      await helper.clickPreviewCancelButton();
+
+      await helper.waitForOverlayClosed();
+      await screenshotExit;
+
+      await assertScreenshotsEvents(CANCEL_EVENTS);
+    }
+  );
+});
+
+add_task(async function test_copy() {
+  await BrowserTestUtils.withNewTab(
+    {
+      gBrowser,
+      url: TEST_PAGE,
+    },
+    async browser => {
+      await clearAllTelemetryEvents();
+      let helper = new ScreenshotsHelper(browser);
+      let contentInfo = await helper.getContentDimensions();
+      ok(contentInfo, "Got dimensions back from the content");
+      let devicePixelRatio = await getContentDevicePixelRatio(browser);
+
+      let expectedWidth = Math.floor(
+        devicePixelRatio * contentInfo.clientWidth
+      );
+      let expectedHeight = Math.floor(
+        devicePixelRatio * contentInfo.clientHeight
+      );
+
+      helper.triggerUIFromToolbar();
+      info("waiting for overlay");
+      await helper.waitForOverlay();
+
+      info("waiting for panel");
+      let panel = await helper.waitForPanel();
+
+      let screenshotReady = TestUtils.topicObserved(
+        "screenshots-preview-ready"
+      );
+
+      // click the visible page button in panel
+      let visiblePageButton = panel
+        .querySelector("screenshots-buttons")
+        .shadowRoot.querySelector(".visible-page");
+      visiblePageButton.click();
+      info("clicked visible page, waiting for screenshots-preview-ready");
+      await screenshotReady;
+
+      let dialog = helper.getDialog();
+      let copyButton = dialog._frame.contentDocument.getElementById("copy");
+
+      let screenshotExit = TestUtils.topicObserved("screenshots-exit");
+      let clipboardChanged = helper.waitForRawClipboardChange(
+        expectedWidth,
+        expectedHeight
+      );
+
+      // click copy button on dialog box
+      info("clicking the copy button");
+      copyButton.click();
+
+      info("Waiting for clipboard change");
+      await clipboardChanged;
+      info("waiting for screenshot exit");
+      await screenshotExit;
+
+      helper.triggerUIFromToolbar();
+      info("waiting for overlay again");
+      await helper.waitForOverlay();
+
+      await helper.dragOverlay(50, 50, 300, 300);
+
+      clipboardChanged = helper.waitForRawClipboardChange(
+        devicePixelRatio * 250,
+        devicePixelRatio * 250
+      );
+
+      screenshotExit = TestUtils.topicObserved("screenshots-exit");
+      await helper.clickCopyButton();
+
+      info("Waiting for clipboard change");
+      await clipboardChanged;
+      info("Waiting for exit again");
+      await screenshotExit;
+
+      info("Waiting for assertScreenshotsEvents");
+      await assertScreenshotsEvents(COPY_EVENTS);
+    }
+  );
+});
+
+add_task(async function test_content_events() {
+  await BrowserTestUtils.withNewTab(
+    {
+      gBrowser,
+      url: TEST_PAGE,
+    },
+    async browser => {
+      await clearAllTelemetryEvents();
+      let helper = new ScreenshotsHelper(browser);
+
+      helper.triggerUIFromToolbar();
+      await helper.waitForOverlay();
+
+      await helper.dragOverlay(50, 50, 300, 300);
+
+      await helper.dragOverlay(300, 300, 333, 333, "selected");
+
+      await helper.dragOverlay(150, 150, 200, 200, "selected");
+
+      mouse.click(11, 11);
+      await helper.assertStateChange("crosshairs");
+
+      await helper.clickTestPageElement();
+
+      let screenshotExit = TestUtils.topicObserved("screenshots-exit");
+
+      await helper.clickCopyButton();
+
+      info("Waiting for exit");
+      await screenshotExit;
+
+      await assertScreenshotsEvents(CONTENT_EVENTS, "content", false);
+      await assertScreenshotsEvents(EXTRA_OVERLAY_EVENTS);
+    }
+  );
+});
+
+add_task(async function test_extra_telemetry() {
+  await BrowserTestUtils.withNewTab(
+    {
+      gBrowser,
+      url: TEST_PAGE,
+    },
+    async browser => {
+      await clearAllTelemetryEvents();
+      let helper = new ScreenshotsHelper(browser);
+      let contentInfo = await helper.getContentDimensions();
+      ok(contentInfo, "Got dimensions back from the content");
+
+      helper.triggerUIFromToolbar();
+      info("waiting for overlay");
+      await helper.waitForOverlay();
+
+      info("waiting for panel");
+      let panel = await helper.waitForPanel();
+
+      let screenshotReady = TestUtils.topicObserved(
+        "screenshots-preview-ready"
+      );
+
+      // click the visible page button in panel
+      let visiblePageButton = panel
+        .querySelector("screenshots-buttons")
+        .shadowRoot.querySelector(".visible-page");
+      visiblePageButton.click();
+      info("clicked visible page, waiting for screenshots-preview-ready");
+      await screenshotReady;
+
+      let dialog = helper.getDialog();
+      let retryButton = dialog._frame.contentDocument.getElementById("retry");
+      retryButton.click();
+
+      info("waiting for panel");
+      panel = await helper.waitForPanel();
+
+      screenshotReady = TestUtils.topicObserved("screenshots-preview-ready");
+
+      // click the full page button in panel
+      let fullPageButton = panel
+        .querySelector("screenshots-buttons")
+        .shadowRoot.querySelector(".full-page");
+      fullPageButton.click();
+      await screenshotReady;
+
+      let screenshotExit = TestUtils.topicObserved("screenshots-exit");
+
+      dialog = helper.getDialog();
+      let copyButton = dialog._frame.contentDocument.getElementById("copy");
+      retryButton.click();
+      // click copy button on dialog box
+      info("clicking the copy button");
+      copyButton.click();
+
+      info("waiting for screenshot exit");
+      await screenshotExit;
+
+      info("Waiting for assertScreenshotsEvents");
+      await assertScreenshotsEvents(EXTRA_EVENTS);
+    }
+  );
+});
diff --git a/browser/components/screenshots/tests/browser/browser_screenshots_test_downloads.js b/browser/components/screenshots/tests/browser/browser_screenshots_test_downloads.js
new file mode 100644
index 0000000000..770a7ae06b
--- /dev/null
+++ b/browser/components/screenshots/tests/browser/browser_screenshots_test_downloads.js
@@ -0,0 +1,186 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+const SCREENSHOTS_EVENTS = [
+  { category: "screenshots", method: "started", object: "toolbar_button" },
+  { category: "screenshots", method: "download", object: "overlay_download" },
+  { category: "screenshots", method: "started", object: "toolbar_button" },
+  { category: "screenshots", method: "selected", object: "visible" },
+  { category: "screenshots", method: "download", object: "preview_download" },
+];
+
+const MockFilePicker = SpecialPowers.MockFilePicker;
+
+add_setup(async function () {
+  let tmpDir = PathUtils.join(
+    PathUtils.tempDir,
+    "testsavedir" + Math.floor(Math.random() * 2 ** 32)
+  );
+  // Create this dir if it doesn't exist (ignores existing dirs)
+  await IOUtils.makeDirectory(tmpDir);
+  await SpecialPowers.pushPrefEnv({
+    set: [
+      ["browser.download.start_downloads_in_tmp_dir", true],
+      ["browser.helperApps.deleteTempFileOnExit", true],
+      ["browser.download.folderList", 2],
+      ["browser.download.dir", tmpDir],
+    ],
+  });
+
+  MockFilePicker.init(window);
+  MockFilePicker.useAnyFile();
+  MockFilePicker.returnValue = MockFilePicker.returnOK;
+
+  registerCleanupFunction(async () => {
+    Services.prefs.clearUserPref("browser.download.dir");
+    Services.prefs.clearUserPref("browser.download.folderList");
+
+    MockFilePicker.cleanup();
+  });
+});
+
+function waitForFilePicker() {
+  return new Promise(resolve => {
+    MockFilePicker.showCallback = () => {
+      MockFilePicker.showCallback = null;
+      ok(true, "Saw the file picker");
+      resolve();
+    };
+  });
+}
+
+add_task(async function test_download_without_filepicker() {
+  await SpecialPowers.pushPrefEnv({
+    set: [["browser.download.useDownloadDir", true]],
+  });
+
+  let publicDownloads = await Downloads.getList(Downloads.PUBLIC);
+  // First ensure we catch the download finishing.
+  let downloadFinishedPromise = new Promise(resolve => {
+    publicDownloads.addView({
+      onDownloadChanged(download) {
+        info("Download changed!");
+        if (download.succeeded || download.error) {
+          info("Download succeeded or errored");
+          publicDownloads.removeView(this);
+          resolve(download);
+        }
+      },
+    });
+  });
+
+  await BrowserTestUtils.withNewTab(
+    {
+      gBrowser,
+      url: TEST_PAGE,
+    },
+    async browser => {
+      await clearAllTelemetryEvents();
+      let helper = new ScreenshotsHelper(browser);
+
+      helper.triggerUIFromToolbar();
+      await helper.waitForOverlay();
+      await helper.dragOverlay(10, 10, 500, 500);
+
+      await helper.clickDownloadButton();
+
+      info("wait for download to finish");
+      let download = await downloadFinishedPromise;
+
+      ok(download.succeeded, "Download should succeed");
+
+      await publicDownloads.removeFinished();
+
+      await waitForScreenshotsEventCount(2);
+
+      helper.triggerUIFromToolbar();
+      await helper.waitForOverlay();
+
+      let screenshotReady = TestUtils.topicObserved(
+        "screenshots-preview-ready"
+      );
+
+      let panel = gBrowser.selectedBrowser.ownerDocument.querySelector(
+        "#screenshotsPagePanel"
+      );
+
+      // click the visible page button in panel
+      let visiblePageButton = panel
+        .querySelector("screenshots-buttons")
+        .shadowRoot.querySelector(".visible-page");
+      visiblePageButton.click();
+
+      let dialog = helper.getDialog();
+
+      await screenshotReady;
+
+      let downloadButton =
+        dialog._frame.contentDocument.getElementById("download");
+      ok(downloadButton, "Got the download button");
+
+      let screenshotExit = TestUtils.topicObserved("screenshots-exit");
+      // click download button on dialog box
+      downloadButton.click();
+
+      info("wait for download to finish");
+      download = await downloadFinishedPromise;
+
+      ok(download.succeeded, "Download should succeed");
+
+      await publicDownloads.removeFinished();
+      await screenshotExit;
+      await assertScreenshotsEvents(SCREENSHOTS_EVENTS);
+    }
+  );
+});
+
+add_task(async function test_download_with_filepicker() {
+  await SpecialPowers.pushPrefEnv({
+    set: [["browser.download.useDownloadDir", false]],
+  });
+
+  let publicDownloads = await Downloads.getList(Downloads.PUBLIC);
+  // First ensure we catch the download finishing.
+  let downloadFinishedPromise = new Promise(resolve => {
+    publicDownloads.addView({
+      onDownloadChanged(download) {
+        info("Download changed!");
+        if (download.succeeded || download.error) {
+          info("Download succeeded or errored");
+          publicDownloads.removeView(this);
+          resolve(download);
+        }
+      },
+    });
+  });
+
+  await BrowserTestUtils.withNewTab(
+    {
+      gBrowser,
+      url: TEST_PAGE,
+    },
+    async browser => {
+      let helper = new ScreenshotsHelper(browser);
+
+      helper.triggerUIFromToolbar();
+      await helper.waitForOverlay();
+      await helper.dragOverlay(10, 10, 500, 500);
+
+      let filePicker = waitForFilePicker();
+      let screenshotExit = TestUtils.topicObserved("screenshots-exit");
+      await helper.clickDownloadButton();
+
+      await filePicker;
+      ok(true, "Export file picker opened");
+
+      info("wait for download to finish");
+      let download = await downloadFinishedPromise;
+
+      ok(download.succeeded, "Download should succeed");
+      await publicDownloads.removeFinished();
+      await screenshotExit;
+    }
+  );
+});
diff --git a/browser/components/screenshots/tests/browser/browser_screenshots_test_escape.js b/browser/components/screenshots/tests/browser/browser_screenshots_test_escape.js
new file mode 100644
index 0000000000..73db436ff1
--- /dev/null
+++ b/browser/components/screenshots/tests/browser/browser_screenshots_test_escape.js
@@ -0,0 +1,35 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+const SCREENSHOTS_EVENTS = [
+  { category: "screenshots", method: "started", object: "toolbar_button" },
+  { category: "screenshots", method: "canceled", object: "escape" },
+];
+
+add_task(async function test_fullpageScreenshot() {
+  await BrowserTestUtils.withNewTab(
+    {
+      gBrowser,
+      url: TEST_PAGE,
+    },
+    async browser => {
+      await clearAllTelemetryEvents();
+      let helper = new ScreenshotsHelper(browser);
+
+      // click toolbar button so panel shows
+      helper.triggerUIFromToolbar();
+
+      await helper.waitForOverlay();
+
+      EventUtils.synthesizeKey("KEY_F6", { shiftKey: true });
+
+      EventUtils.synthesizeKey("KEY_Escape");
+
+      await helper.waitForOverlayClosed();
+
+      await assertScreenshotsEvents(SCREENSHOTS_EVENTS);
+    }
+  );
+});
diff --git a/browser/components/screenshots/tests/browser/browser_screenshots_test_full_page.js b/browser/components/screenshots/tests/browser/browser_screenshots_test_full_page.js
new file mode 100644
index 0000000000..51cda963d9
--- /dev/null
+++ b/browser/components/screenshots/tests/browser/browser_screenshots_test_full_page.js
@@ -0,0 +1,175 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+function assertRange(lhs, rhsMin, rhsMax, msg) {
+  Assert.ok(lhs >= rhsMin && lhs <= rhsMax, msg);
+}
+
+add_task(async function test_fullpageScreenshot() {
+  await BrowserTestUtils.withNewTab(
+    {
+      gBrowser,
+      url: TEST_PAGE,
+    },
+    async browser => {
+      let helper = new ScreenshotsHelper(browser);
+      let contentInfo = await helper.getContentDimensions();
+      ok(contentInfo, "Got dimensions back from the content");
+      let devicePixelRatio = await getContentDevicePixelRatio(browser);
+
+      let expectedWidth = Math.floor(
+        devicePixelRatio * contentInfo.scrollWidth
+      );
+      let expectedHeight = Math.floor(
+        devicePixelRatio * contentInfo.scrollHeight
+      );
+
+      // click toolbar button so panel shows
+      helper.triggerUIFromToolbar();
+
+      let panel = await helper.waitForPanel();
+
+      let screenshotReady = TestUtils.topicObserved(
+        "screenshots-preview-ready"
+      );
+
+      // click the full page button in panel
+      let visiblePage = panel
+        .querySelector("screenshots-buttons")
+        .shadowRoot.querySelector(".full-page");
+      visiblePage.click();
+
+      let dialog = helper.getDialog();
+
+      await screenshotReady;
+
+      let copyButton = dialog._frame.contentDocument.getElementById("copy");
+      ok(copyButton, "Got the copy button");
+
+      let clipboardChanged = helper.waitForRawClipboardChange(
+        expectedWidth,
+        expectedHeight
+      );
+
+      // click copy button on dialog box
+      copyButton.click();
+
+      info("Waiting for clipboard change");
+      let result = await clipboardChanged;
+
+      info("result: " + JSON.stringify(result, null, 2));
+      info("contentInfo: " + JSON.stringify(contentInfo, null, 2));
+
+      Assert.equal(result.width, expectedWidth, "Widths should be equal");
+      Assert.equal(result.height, expectedHeight, "Heights should be equal");
+
+      // top left
+      assertRange(result.color.topLeft[0], 110, 111, "R color value");
+      assertRange(result.color.topLeft[1], 110, 111, "G color value");
+      assertRange(result.color.topLeft[2], 110, 111, "B color value");
+
+      // top right
+      assertRange(result.color.topRight[0], 55, 56, "R color value");
+      assertRange(result.color.topRight[1], 155, 156, "G color value");
+      assertRange(result.color.topRight[2], 155, 156, "B color value");
+
+      // bottom left
+      assertRange(result.color.bottomLeft[0], 105, 106, "R color value");
+      assertRange(result.color.bottomLeft[1], 55, 56, "G color value");
+      assertRange(result.color.bottomLeft[2], 105, 106, "B color value");
+
+      // bottom right
+      assertRange(result.color.bottomRight[0], 52, 53, "R color value");
+      assertRange(result.color.bottomRight[1], 127, 128, "G color value");
+      assertRange(result.color.bottomRight[2], 152, 153, "B color value");
+    }
+  );
+});
+
+add_task(async function test_fullpageScreenshotScrolled() {
+  await BrowserTestUtils.withNewTab(
+    {
+      gBrowser,
+      url: TEST_PAGE,
+    },
+    async browser => {
+      let helper = new ScreenshotsHelper(browser);
+
+      await SpecialPowers.spawn(browser, [], () => {
+        content.scrollTo(0, 2008);
+      });
+      let contentInfo = await helper.getContentDimensions();
+      ok(contentInfo, "Got dimensions back from the content");
+      let devicePixelRatio = await getContentDevicePixelRatio(browser);
+
+      let expectedWidth = Math.floor(
+        devicePixelRatio * contentInfo.scrollWidth
+      );
+      let expectedHeight = Math.floor(
+        devicePixelRatio * contentInfo.scrollHeight
+      );
+
+      // click toolbar button so panel shows
+      helper.triggerUIFromToolbar();
+      await helper.waitForOverlay();
+
+      let panel = await helper.waitForPanel();
+
+      let screenshotReady = TestUtils.topicObserved(
+        "screenshots-preview-ready"
+      );
+
+      // click the full page button in panel
+      let visiblePage = panel
+        .querySelector("screenshots-buttons")
+        .shadowRoot.querySelector(".full-page");
+      visiblePage.click();
+
+      let dialog = helper.getDialog();
+
+      await screenshotReady;
+
+      let copyButton = dialog._frame.contentDocument.getElementById("copy");
+      ok(copyButton, "Got the copy button");
+
+      let clipboardChanged = helper.waitForRawClipboardChange(
+        expectedWidth,
+        expectedHeight
+      );
+
+      // click copy button on dialog box
+      copyButton.click();
+
+      info("Waiting for clipboard change");
+      let result = await clipboardChanged;
+
+      info("result: " + JSON.stringify(result, null, 2));
+      info("contentInfo: " + JSON.stringify(contentInfo, null, 2));
+
+      Assert.equal(result.width, expectedWidth, "Widths should be equal");
+      Assert.equal(result.height, expectedHeight, "Heights should be equal");
+
+      // top left
+      assertRange(result.color.topLeft[0], 110, 111, "R color value");
+      assertRange(result.color.topLeft[1], 110, 111, "G color value");
+      assertRange(result.color.topLeft[2], 110, 111, "B color value");
+
+      // top right
+      assertRange(result.color.topRight[0], 55, 56, "R color value");
+      assertRange(result.color.topRight[1], 155, 156, "G color value");
+      assertRange(result.color.topRight[2], 155, 156, "B color value");
+
+      // bottom left
+      assertRange(result.color.bottomLeft[0], 105, 106, "R color value");
+      assertRange(result.color.bottomLeft[1], 55, 56, "G color value");
+      assertRange(result.color.bottomLeft[2], 105, 106, "B color value");
+
+      // bottom right
+      assertRange(result.color.bottomRight[0], 52, 53, "R color value");
+      assertRange(result.color.bottomRight[1], 127, 128, "G color value");
+      assertRange(result.color.bottomRight[2], 152, 153, "B color value");
+    }
+  );
+});
diff --git a/browser/components/screenshots/tests/browser/browser_screenshots_test_page_crash.js b/browser/components/screenshots/tests/browser/browser_screenshots_test_page_crash.js
new file mode 100644
index 0000000000..bed9d006db
--- /dev/null
+++ b/browser/components/screenshots/tests/browser/browser_screenshots_test_page_crash.js
@@ -0,0 +1,54 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+add_task(async function test_fullpageScreenshot() {
+  await BrowserTestUtils.withNewTab(
+    {
+      gBrowser,
+      url: TEST_PAGE,
+    },
+    async browser => {
+      let helper = new ScreenshotsHelper(browser);
+
+      // click toolbar button so UI shows
+      helper.triggerUIFromToolbar();
+      await helper.waitForOverlay();
+
+      let panel = await helper.waitForPanel(gBrowser.selectedBrowser);
+
+      let waitForPanelHide = BrowserTestUtils.waitForMutationCondition(
+        panel,
+        { attributes: true },
+        () => {
+          return BrowserTestUtils.isHidden(panel);
+        }
+      );
+
+      await BrowserTestUtils.crashFrame(browser);
+
+      await waitForPanelHide;
+      ok(
+        BrowserTestUtils.isHidden(panel),
+        "Panel buttons are hidden after page crash"
+      );
+
+      await ContentTask.spawn(browser, null, async () => {
+        let screenshotsChild = content.windowGlobalChild.getActor(
+          "ScreenshotsComponent"
+        );
+        Assert.ok(!screenshotsChild._overlay, "The overlay doesn't exist");
+      });
+
+      let tab = gBrowser.getTabForBrowser(browser);
+
+      SessionStore.reviveCrashedTab(tab);
+
+      ok(
+        BrowserTestUtils.isHidden(panel),
+        "Panel buttons are hidden after page crash"
+      );
+    }
+  );
+});
diff --git a/browser/components/screenshots/tests/browser/browser_screenshots_test_screenshot_too_big.js b/browser/components/screenshots/tests/browser/browser_screenshots_test_screenshot_too_big.js
new file mode 100644
index 0000000000..4e2da3d494
--- /dev/null
+++ b/browser/components/screenshots/tests/browser/browser_screenshots_test_screenshot_too_big.js
@@ -0,0 +1,90 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+const SCREENSHOTS_EVENTS = [
+  { category: "screenshots", method: "failed", object: "screenshot_too_large" },
+  { category: "screenshots", method: "failed", object: "screenshot_too_large" },
+  { category: "screenshots", method: "failed", object: "screenshot_too_large" },
+  { category: "screenshots", method: "failed", object: "screenshot_too_large" },
+];
+
+const { sinon } = ChromeUtils.importESModule(
+  "resource://testing-common/Sinon.sys.mjs"
+);
+ChromeUtils.defineESModuleGetters(this, {
+  ScreenshotsUtils: "resource:///modules/ScreenshotsUtils.sys.mjs",
+});
+
+add_task(async function test_screenshot_too_large_cropped() {
+  await clearAllTelemetryEvents();
+  const screenshotsLocalization = new Localization(
+    ["browser/screenshots.ftl"],
+    true
+  );
+
+  let [errorTitle, errorMessage] = screenshotsLocalization.formatMessagesSync([
+    { id: "screenshots-too-large-error-title" },
+    { id: "screenshots-too-large-error-details" },
+  ]);
+  let showAlertMessageStub = sinon
+    .stub(ScreenshotsUtils, "showAlertMessage")
+    .callsFake(function (title, message) {
+      is(title, errorTitle.value, "Got error title");
+      is(message, errorMessage.value, "Got error message");
+    });
+
+  let rect = { x: 0, y: 0, width: 40000, height: 40000, devicePixelRatio: 1 };
+
+  ScreenshotsUtils.cropScreenshotRectIfNeeded(rect);
+
+  is(
+    rect.width,
+    MAX_CAPTURE_DIMENSION,
+    `The width is ${MAX_CAPTURE_DIMENSION}`
+  );
+  is(
+    rect.height,
+    Math.floor(MAX_CAPTURE_AREA / MAX_CAPTURE_DIMENSION),
+    `The height is ${MAX_CAPTURE_AREA} / ${MAX_CAPTURE_DIMENSION}`
+  );
+
+  rect.width = 40000;
+  rect.hegith = 1;
+
+  ScreenshotsUtils.cropScreenshotRectIfNeeded(rect);
+
+  is(
+    rect.width,
+    MAX_CAPTURE_DIMENSION,
+    `The width was cropped to the max capture dimension (${MAX_CAPTURE_DIMENSION}).`
+  );
+
+  rect.width = 1;
+  rect.height = 40000;
+
+  ScreenshotsUtils.cropScreenshotRectIfNeeded(rect);
+
+  is(
+    rect.height,
+    MAX_CAPTURE_DIMENSION,
+    `The height was cropped to the max capture dimension (${MAX_CAPTURE_DIMENSION}).`
+  );
+
+  rect.width = 25000;
+  rect.height = 25000;
+
+  ScreenshotsUtils.cropScreenshotRectIfNeeded(rect);
+
+  is(rect.width, 25000, "The width was not cropped");
+  is(
+    rect.height,
+    Math.floor(MAX_CAPTURE_AREA / 25000),
+    `The height was cropped to ${MAX_CAPTURE_AREA / 25000}`
+  );
+
+  showAlertMessageStub.restore();
+
+  await assertScreenshotsEvents(SCREENSHOTS_EVENTS);
+});
diff --git a/browser/components/screenshots/tests/browser/browser_screenshots_test_toggle_pref.js b/browser/components/screenshots/tests/browser/browser_screenshots_test_toggle_pref.js
new file mode 100644
index 0000000000..0aafba8fb3
--- /dev/null
+++ b/browser/components/screenshots/tests/browser/browser_screenshots_test_toggle_pref.js
@@ -0,0 +1,289 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+const { sinon } = ChromeUtils.importESModule(
+  "resource://testing-common/Sinon.sys.mjs"
+);
+
+ChromeUtils.defineESModuleGetters(this, {
+  ScreenshotsUtils: "resource:///modules/ScreenshotsUtils.sys.mjs",
+});
+ChromeUtils.defineLazyGetter(this, "ExtensionManagement", () => {
+  const { Management } = ChromeUtils.importESModule(
+    "resource://gre/modules/Extension.sys.mjs"
+  );
+  return Management;
+});
+
+add_task(async function test() {
+  let observerSpy = sinon.spy();
+  let notifierSpy = sinon.spy();
+
+  let observerStub = sinon
+    .stub(ScreenshotsUtils, "observe")
+    .callsFake(observerSpy);
+  let notifierStub = sinon
+    .stub(ScreenshotsUtils, "notify")
+    .callsFake(function (window, type) {
+      notifierSpy();
+      ScreenshotsUtils.notify.wrappedMethod.apply(this, arguments);
+    });
+
+  await BrowserTestUtils.withNewTab(
+    {
+      gBrowser,
+      url: SHORT_TEST_PAGE,
+    },
+    async browser => {
+      function awaitExtensionEvent(eventName, id) {
+        return new Promise(resolve => {
+          let listener = (_eventName, ...args) => {
+            let extension = args[0];
+            if (_eventName === eventName && extension.id == id) {
+              ExtensionManagement.off(eventName, listener);
+              resolve();
+            }
+          };
+          ExtensionManagement.on(eventName, listener);
+        });
+      }
+      const SCREENSHOT_EXTENSION = "screenshots@mozilla.org";
+
+      let helper = new ScreenshotsHelper(browser);
+
+      ok(observerSpy.notCalled, "Observer not called");
+      helper.triggerUIFromToolbar();
+      Assert.equal(observerSpy.callCount, 1, "Observer function called once");
+
+      ok(notifierSpy.notCalled, "Notifier not called");
+      EventUtils.synthesizeKey("s", { accelKey: true, shiftKey: true });
+
+      await TestUtils.waitForCondition(() => notifierSpy.callCount == 1);
+      Assert.equal(notifierSpy.callCount, 1, "Notify function called once");
+
+      await TestUtils.waitForCondition(() => observerSpy.callCount == 2);
+      Assert.equal(observerSpy.callCount, 2, "Observer function called twice");
+
+      let menu = document.getElementById("contentAreaContextMenu");
+      let popupshown = BrowserTestUtils.waitForPopupEvent(menu, "shown");
+      EventUtils.synthesizeMouseAtCenter(document.body, {
+        type: "contextmenu",
+      });
+      await popupshown;
+      Assert.equal(menu.state, "open", "Context menu is open");
+
+      let popuphidden = BrowserTestUtils.waitForPopupEvent(menu, "hidden");
+      menu.activateItem(menu.querySelector("#context-take-screenshot"));
+      await popuphidden;
+
+      Assert.equal(observerSpy.callCount, 3, "Observer function called thrice");
+
+      const COMPONENT_PREF = "screenshots.browser.component.enabled";
+      await SpecialPowers.pushPrefEnv({
+        set: [[COMPONENT_PREF, false]],
+      });
+      ok(!Services.prefs.getBoolPref(COMPONENT_PREF), "Extension enabled");
+      await awaitExtensionEvent("ready", SCREENSHOT_EXTENSION);
+
+      helper.triggerUIFromToolbar();
+      Assert.equal(
+        observerSpy.callCount,
+        3,
+        "Observer function still called thrice"
+      );
+
+      await SpecialPowers.spawn(
+        browser,
+        ["#firefox-screenshots-preselection-iframe"],
+        async function (iframeSelector) {
+          info(
+            `in waitForUIContent content function, iframeSelector: ${iframeSelector}`
+          );
+          let iframe;
+          await ContentTaskUtils.waitForCondition(() => {
+            iframe = content.document.querySelector(iframeSelector);
+            if (!iframe || !ContentTaskUtils.isVisible(iframe)) {
+              info("in waitForUIContent, no visible iframe yet");
+              return false;
+            }
+            return true;
+          });
+          // wait a frame for the screenshots UI to finish any init
+          await new content.Promise(res => content.requestAnimationFrame(res));
+        }
+      );
+
+      helper.triggerUIFromToolbar();
+      await SpecialPowers.spawn(
+        browser,
+        ["#firefox-screenshots-preselection-iframe"],
+        async function (iframeSelector) {
+          info(
+            `in waitForUIContent content function, iframeSelector: ${iframeSelector}`
+          );
+          let iframe;
+          await ContentTaskUtils.waitForCondition(() => {
+            iframe = content.document.querySelector(iframeSelector);
+            if (!iframe || !ContentTaskUtils.isVisible(iframe)) {
+              info("in waitForUIContent, no visible iframe yet");
+              return true;
+            }
+            return false;
+          });
+          // wait a frame for the screenshots UI to finish any init
+          await new content.Promise(res => content.requestAnimationFrame(res));
+        }
+      );
+
+      popupshown = BrowserTestUtils.waitForPopupEvent(menu, "shown");
+      EventUtils.synthesizeMouseAtCenter(document.body, {
+        type: "contextmenu",
+      });
+      await popupshown;
+      Assert.equal(menu.state, "open", "Context menu is open");
+
+      popuphidden = BrowserTestUtils.waitForPopupEvent(menu, "hidden");
+      menu.activateItem(menu.querySelector("#context-take-screenshot"));
+      await popuphidden;
+
+      Assert.equal(
+        observerSpy.callCount,
+        3,
+        "Observer function still called thrice"
+      );
+
+      await SpecialPowers.spawn(
+        browser,
+        ["#firefox-screenshots-preselection-iframe"],
+        async function (iframeSelector) {
+          info(
+            `in waitForUIContent content function, iframeSelector: ${iframeSelector}`
+          );
+          let iframe;
+          await ContentTaskUtils.waitForCondition(() => {
+            iframe = content.document.querySelector(iframeSelector);
+            if (!iframe || !ContentTaskUtils.isVisible(iframe)) {
+              info("in waitForUIContent, no visible iframe yet");
+              return false;
+            }
+            return true;
+          });
+          // wait a frame for the screenshots UI to finish any init
+          await new content.Promise(res => content.requestAnimationFrame(res));
+        }
+      );
+
+      helper.triggerUIFromToolbar();
+      await SpecialPowers.spawn(
+        browser,
+        ["#firefox-screenshots-preselection-iframe"],
+        async function (iframeSelector) {
+          info(
+            `in waitForUIContent content function, iframeSelector: ${iframeSelector}`
+          );
+          let iframe;
+          await ContentTaskUtils.waitForCondition(() => {
+            iframe = content.document.querySelector(iframeSelector);
+            if (!iframe || !ContentTaskUtils.isVisible(iframe)) {
+              return true;
+            }
+            info("in waitForUIContent, iframe still visible");
+            info(iframe);
+            return false;
+          });
+          // wait a frame for the screenshots UI to finish any init
+          await new content.Promise(res => content.requestAnimationFrame(res));
+        }
+      );
+
+      let componentReady = TestUtils.topicObserved(
+        "screenshots-component-initialized"
+      );
+
+      await SpecialPowers.pushPrefEnv({
+        set: [[COMPONENT_PREF, true]],
+      });
+      ok(Services.prefs.getBoolPref(COMPONENT_PREF), "Component enabled");
+      // Needed for component to initialize
+      await componentReady;
+
+      helper.triggerUIFromToolbar();
+      Assert.equal(
+        observerSpy.callCount,
+        4,
+        "Observer function called four times"
+      );
+
+      const SCREENSHOTS_PREF = "extensions.screenshots.disabled";
+      await SpecialPowers.pushPrefEnv({
+        set: [[SCREENSHOTS_PREF, true]],
+      });
+      ok(Services.prefs.getBoolPref(SCREENSHOTS_PREF), "Screenshots disabled");
+    }
+  );
+
+  await BrowserTestUtils.withNewTab(
+    {
+      gBrowser,
+      url: SHORT_TEST_PAGE,
+    },
+    async browser => {
+      const SCREENSHOTS_PREF = "extensions.screenshots.disabled";
+      ok(Services.prefs.getBoolPref(SCREENSHOTS_PREF), "Screenshots disabled");
+
+      ok(
+        document.getElementById("screenshot-button").disabled,
+        "Toolbar button disabled"
+      );
+
+      let menu = document.getElementById("contentAreaContextMenu");
+      let popupshown = BrowserTestUtils.waitForPopupEvent(menu, "shown");
+      EventUtils.synthesizeMouseAtCenter(document.body, {
+        type: "contextmenu",
+      });
+      await popupshown;
+      Assert.equal(menu.state, "open", "Context menu is open");
+
+      ok(
+        menu.querySelector("#context-take-screenshot").hidden,
+        "Take screenshot is not in context menu"
+      );
+
+      let popuphidden = BrowserTestUtils.waitForPopupEvent(menu, "hidden");
+      menu.hidePopup();
+      await popuphidden;
+
+      await SpecialPowers.pushPrefEnv({
+        set: [[SCREENSHOTS_PREF, false]],
+      });
+      ok(!Services.prefs.getBoolPref(SCREENSHOTS_PREF), "Screenshots enabled");
+    }
+  );
+
+  await BrowserTestUtils.withNewTab(
+    {
+      gBrowser,
+      url: SHORT_TEST_PAGE,
+    },
+    async browser => {
+      const SCREENSHOTS_PREF = "extensions.screenshots.disabled";
+      ok(!Services.prefs.getBoolPref(SCREENSHOTS_PREF), "Screenshots enabled");
+
+      let helper = new ScreenshotsHelper(browser);
+
+      helper.triggerUIFromToolbar();
+      Assert.equal(
+        observerSpy.callCount,
+        5,
+        "Observer function called for the fifth time"
+      );
+    }
+  );
+
+  observerStub.restore();
+  notifierStub.restore();
+
+  await SpecialPowers.popPrefEnv();
+});
diff --git a/browser/components/screenshots/tests/browser/browser_screenshots_test_toolbar_button.js b/browser/components/screenshots/tests/browser/browser_screenshots_test_toolbar_button.js
new file mode 100644
index 0000000000..5ad7d32192
--- /dev/null
+++ b/browser/components/screenshots/tests/browser/browser_screenshots_test_toolbar_button.js
@@ -0,0 +1,26 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+add_task(async function testScreenshotButtonDisabled() {
+  info("Test the Screenshots button in the panel");
+
+  let screenshotBtn = document.getElementById("screenshot-button");
+  Assert.ok(screenshotBtn, "The screenshots button was added to the nav bar");
+
+  await BrowserTestUtils.withNewTab("https://example.com/", () => {
+    Assert.equal(
+      screenshotBtn.disabled,
+      false,
+      "Screenshots button is enabled"
+    );
+  });
+  await BrowserTestUtils.withNewTab("about:home", () => {
+    Assert.equal(
+      screenshotBtn.disabled,
+      false,
+      "Screenshots button is still enabled on about pages"
+    );
+  });
+});
diff --git a/browser/components/screenshots/tests/browser/browser_screenshots_test_visible.js b/browser/components/screenshots/tests/browser/browser_screenshots_test_visible.js
new file mode 100644
index 0000000000..7b7a46f73d
--- /dev/null
+++ b/browser/components/screenshots/tests/browser/browser_screenshots_test_visible.js
@@ -0,0 +1,356 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+add_task(async function test_visibleScreenshot() {
+  await BrowserTestUtils.withNewTab(
+    {
+      gBrowser,
+      url: TEST_PAGE,
+    },
+    async browser => {
+      let helper = new ScreenshotsHelper(browser);
+      let contentInfo = await helper.getContentDimensions();
+      ok(contentInfo, "Got dimensions back from the content");
+      let devicePixelRatio = await getContentDevicePixelRatio(browser);
+
+      let expectedWidth = Math.floor(
+        devicePixelRatio * contentInfo.clientWidth
+      );
+      let expectedHeight = Math.floor(
+        devicePixelRatio * contentInfo.clientHeight
+      );
+
+      // click toolbar button so panel shows
+      helper.triggerUIFromToolbar();
+
+      await helper.waitForOverlay();
+
+      let screenshotReady = TestUtils.topicObserved(
+        "screenshots-preview-ready"
+      );
+
+      let panel = gBrowser.selectedBrowser.ownerDocument.querySelector(
+        "#screenshotsPagePanel"
+      );
+
+      // click the visible page button in panel
+      let visiblePageButton = panel
+        .querySelector("screenshots-buttons")
+        .shadowRoot.querySelector(".visible-page");
+      visiblePageButton.click();
+
+      let dialog = helper.getDialog();
+
+      await screenshotReady;
+
+      let copyButton = dialog._frame.contentDocument.getElementById("copy");
+      ok(copyButton, "Got the copy button");
+
+      let clipboardChanged = helper.waitForRawClipboardChange(
+        expectedWidth,
+        expectedHeight
+      );
+
+      // click copy button on dialog box
+      copyButton.click();
+
+      info("Waiting for clipboard change");
+      let result = await clipboardChanged;
+
+      info("result: " + JSON.stringify(result, null, 2));
+      info("contentInfo: " + JSON.stringify(contentInfo, null, 2));
+
+      Assert.equal(result.width, expectedWidth, "Widths should be equal");
+      Assert.equal(result.height, expectedHeight, "Heights should be equal");
+
+      // top left
+      Assert.equal(111, result.color.topLeft[0], "R color value");
+      Assert.equal(111, result.color.topLeft[1], "G color value");
+      Assert.equal(111, result.color.topLeft[2], "B color value");
+
+      // top right
+      Assert.equal(111, result.color.topRight[0], "R color value");
+      Assert.equal(111, result.color.topRight[1], "G color value");
+      Assert.equal(111, result.color.topRight[2], "B color value");
+
+      // bottom left
+      Assert.equal(111, result.color.bottomLeft[0], "R color value");
+      Assert.equal(111, result.color.bottomLeft[1], "G color value");
+      Assert.equal(111, result.color.bottomLeft[2], "B color value");
+
+      // bottom right
+      Assert.equal(111, result.color.bottomRight[0], "R color value");
+      Assert.equal(111, result.color.bottomRight[1], "G color value");
+      Assert.equal(111, result.color.bottomRight[2], "B color value");
+    }
+  );
+});
+
+add_task(async function test_visibleScreenshotScrolledY() {
+  await BrowserTestUtils.withNewTab(
+    {
+      gBrowser,
+      url: TEST_PAGE,
+    },
+    async browser => {
+      await SpecialPowers.spawn(browser, [], () => {
+        content.scrollTo(0, 2008);
+      });
+
+      let helper = new ScreenshotsHelper(browser);
+      let contentInfo = await helper.getContentDimensions();
+      ok(contentInfo, "Got dimensions back from the content");
+      let devicePixelRatio = await getContentDevicePixelRatio(browser);
+
+      let expectedWidth = Math.floor(
+        devicePixelRatio * contentInfo.clientWidth
+      );
+      let expectedHeight = Math.floor(
+        devicePixelRatio * contentInfo.clientHeight
+      );
+
+      // click toolbar button so panel shows
+      helper.triggerUIFromToolbar();
+      await helper.waitForOverlay();
+
+      let panel = gBrowser.selectedBrowser.ownerDocument.querySelector(
+        "#screenshotsPagePanel"
+      );
+
+      let screenshotReady = TestUtils.topicObserved(
+        "screenshots-preview-ready"
+      );
+
+      // click the visible page button in panel
+      let visiblePageButton = panel
+        .querySelector("screenshots-buttons")
+        .shadowRoot.querySelector(".visible-page");
+      visiblePageButton.click();
+
+      let dialog = helper.getDialog();
+
+      await screenshotReady;
+
+      let copyButton = dialog._frame.contentDocument.getElementById("copy");
+      ok(copyButton, "Got the copy button");
+
+      let clipboardChanged = helper.waitForRawClipboardChange(
+        expectedWidth,
+        expectedHeight
+      );
+
+      // click copy button on dialog box
+      copyButton.click();
+
+      info("Waiting for clipboard change");
+      let result = await clipboardChanged;
+
+      // let result = await helper.getImageSizeAndColorFromClipboard();
+      // debugger;
+
+      info("result: " + JSON.stringify(result, null, 2));
+      info("contentInfo: " + JSON.stringify(contentInfo, null, 2));
+
+      Assert.equal(result.width, expectedWidth, "Widths should be equal");
+      Assert.equal(result.height, expectedHeight, "Heights should be equal");
+
+      // top left
+      Assert.equal(105, result.color.topLeft[0], "R color value");
+      Assert.equal(55, result.color.topLeft[1], "G color value");
+      Assert.equal(105, result.color.topLeft[2], "B color value");
+
+      // top right
+      Assert.equal(105, result.color.topRight[0], "R color value");
+      Assert.equal(55, result.color.topRight[1], "G color value");
+      Assert.equal(105, result.color.topRight[2], "B color value");
+
+      // bottom left
+      Assert.equal(105, result.color.bottomLeft[0], "R color value");
+      Assert.equal(55, result.color.bottomLeft[1], "G color value");
+      Assert.equal(105, result.color.bottomLeft[2], "B color value");
+
+      // bottom right
+      Assert.equal(105, result.color.bottomRight[0], "R color value");
+      Assert.equal(55, result.color.bottomRight[1], "G color value");
+      Assert.equal(105, result.color.bottomRight[2], "B color value");
+    }
+  );
+});
+
+add_task(async function test_visibleScreenshotScrolledX() {
+  await BrowserTestUtils.withNewTab(
+    {
+      gBrowser,
+      url: TEST_PAGE,
+    },
+    async browser => {
+      await SpecialPowers.spawn(browser, [], () => {
+        content.scrollTo(2004, 0);
+      });
+
+      let helper = new ScreenshotsHelper(browser);
+      let contentInfo = await helper.getContentDimensions();
+      ok(contentInfo, "Got dimensions back from the content");
+      let devicePixelRatio = await getContentDevicePixelRatio(browser);
+
+      let expectedWidth = Math.floor(
+        devicePixelRatio * contentInfo.clientWidth
+      );
+      let expectedHeight = Math.floor(
+        devicePixelRatio * contentInfo.clientHeight
+      );
+
+      // click toolbar button so panel shows
+      helper.triggerUIFromToolbar();
+      await helper.waitForOverlay();
+
+      let panel = gBrowser.selectedBrowser.ownerDocument.querySelector(
+        "#screenshotsPagePanel"
+      );
+
+      let screenshotReady = TestUtils.topicObserved(
+        "screenshots-preview-ready"
+      );
+
+      // click the visible page button in panel
+      let visiblePageButton = panel
+        .querySelector("screenshots-buttons")
+        .shadowRoot.querySelector(".visible-page");
+      visiblePageButton.click();
+
+      let dialog = helper.getDialog();
+
+      await screenshotReady;
+
+      let copyButton = dialog._frame.contentDocument.getElementById("copy");
+      ok(copyButton, "Got the copy button");
+
+      let clipboardChanged = helper.waitForRawClipboardChange(
+        expectedWidth,
+        expectedHeight
+      );
+
+      // click copy button on dialog box
+      copyButton.click();
+
+      info("Waiting for clipboard change");
+      let result = await clipboardChanged;
+
+      info("result: " + JSON.stringify(result, null, 2));
+      info("contentInfo: " + JSON.stringify(contentInfo, null, 2));
+
+      Assert.equal(result.width, expectedWidth, "Widths should be equal");
+      Assert.equal(result.height, expectedHeight, "Heights should be equal");
+
+      // top left
+      Assert.equal(55, result.color.topLeft[0], "R color value");
+      Assert.equal(155, result.color.topLeft[1], "G color value");
+      Assert.equal(155, result.color.topLeft[2], "B color value");
+
+      // top right
+      Assert.equal(55, result.color.topRight[0], "R color value");
+      Assert.equal(155, result.color.topRight[1], "G color value");
+      Assert.equal(155, result.color.topRight[2], "B color value");
+
+      // bottom left
+      Assert.equal(55, result.color.bottomLeft[0], "R color value");
+      Assert.equal(155, result.color.bottomLeft[1], "G color value");
+      Assert.equal(155, result.color.bottomLeft[2], "B color value");
+
+      // bottom right
+      Assert.equal(55, result.color.bottomRight[0], "R color value");
+      Assert.equal(155, result.color.bottomRight[1], "G color value");
+      Assert.equal(155, result.color.bottomRight[2], "B color value");
+    }
+  );
+});
+
+add_task(async function test_visibleScreenshotScrolledXAndY() {
+  await BrowserTestUtils.withNewTab(
+    {
+      gBrowser,
+      url: TEST_PAGE,
+    },
+    async browser => {
+      await SpecialPowers.spawn(browser, [], () => {
+        content.scrollTo(2004, 2008);
+      });
+
+      let helper = new ScreenshotsHelper(browser);
+      let contentInfo = await helper.getContentDimensions();
+      ok(contentInfo, "Got dimensions back from the content");
+      let devicePixelRatio = await getContentDevicePixelRatio(browser);
+
+      let expectedWidth = Math.floor(
+        devicePixelRatio * contentInfo.clientWidth
+      );
+      let expectedHeight = Math.floor(
+        devicePixelRatio * contentInfo.clientHeight
+      );
+
+      // click toolbar button so panel shows
+      helper.triggerUIFromToolbar();
+      await helper.waitForOverlay();
+
+      let panel = gBrowser.selectedBrowser.ownerDocument.querySelector(
+        "#screenshotsPagePanel"
+      );
+
+      let screenshotReady = TestUtils.topicObserved(
+        "screenshots-preview-ready"
+      );
+
+      // click the visible page button in panel
+      let visiblePageButton = panel
+        .querySelector("screenshots-buttons")
+        .shadowRoot.querySelector(".visible-page");
+      visiblePageButton.click();
+
+      let dialog = helper.getDialog();
+
+      await screenshotReady;
+
+      let copyButton = dialog._frame.contentDocument.getElementById("copy");
+      ok(copyButton, "Got the copy button");
+
+      let clipboardChanged = helper.waitForRawClipboardChange(
+        expectedWidth,
+        expectedHeight
+      );
+
+      // click copy button on dialog box
+      copyButton.click();
+
+      info("Waiting for clipboard change");
+      let result = await clipboardChanged;
+
+      info("result: " + JSON.stringify(result, null, 2));
+      info("contentInfo: " + JSON.stringify(contentInfo, null, 2));
+
+      Assert.equal(result.width, expectedWidth, "Widths should be equal");
+      Assert.equal(result.height, expectedHeight, "Heights should be equal");
+
+      // top left
+      Assert.equal(52, result.color.topLeft[0], "R color value");
+      Assert.equal(127, result.color.topLeft[1], "G color value");
+      Assert.equal(152, result.color.topLeft[2], "B color value");
+
+      // top right
+      Assert.equal(52, result.color.topRight[0], "R color value");
+      Assert.equal(127, result.color.topRight[1], "G color value");
+      Assert.equal(152, result.color.topRight[2], "B color value");
+
+      // bottom left
+      Assert.equal(52, result.color.bottomLeft[0], "R color value");
+      Assert.equal(127, result.color.bottomLeft[1], "G color value");
+      Assert.equal(152, result.color.bottomLeft[2], "B color value");
+
+      // bottom right
+      Assert.equal(52, result.color.bottomRight[0], "R color value");
+      Assert.equal(127, result.color.bottomRight[1], "G color value");
+      Assert.equal(152, result.color.bottomRight[2], "B color value");
+    }
+  );
+});
diff --git a/browser/components/screenshots/tests/browser/browser_test_element_picker.js b/browser/components/screenshots/tests/browser/browser_test_element_picker.js
new file mode 100644
index 0000000000..17ed2a0190
--- /dev/null
+++ b/browser/components/screenshots/tests/browser/browser_test_element_picker.js
@@ -0,0 +1,56 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+add_task(async function test_element_picker() {
+  await BrowserTestUtils.withNewTab(
+    {
+      gBrowser,
+      url: TEST_PAGE,
+    },
+    async browser => {
+      await clearAllTelemetryEvents();
+      let helper = new ScreenshotsHelper(browser);
+
+      helper.triggerUIFromToolbar();
+      await helper.waitForOverlay();
+
+      await helper.clickTestPageElement();
+
+      let rect = await helper.getTestPageElementRect();
+      let region = await helper.getSelectionRegionDimensions();
+
+      is(
+        region.left,
+        rect.left,
+        "The selected region left is the same as the element left"
+      );
+      is(
+        region.right,
+        rect.right,
+        "The selected region right is the same as the element right"
+      );
+      is(
+        region.top,
+        rect.top,
+        "The selected region top is the same as the element top"
+      );
+      is(
+        region.bottom,
+        rect.bottom,
+        "The selected region bottom is the same as the element bottom"
+      );
+
+      mouse.click(10, 10);
+      await helper.waitForStateChange("crosshairs");
+
+      let hoverElementRegionValid = await helper.isHoverElementRegionValid();
+
+      ok(!hoverElementRegionValid, "Hover element rect is null");
+
+      mouse.click(10, 10);
+      await helper.waitForStateChange("crosshairs");
+    }
+  );
+});
diff --git a/browser/components/screenshots/tests/browser/browser_test_resize.js b/browser/components/screenshots/tests/browser/browser_test_resize.js
new file mode 100644
index 0000000000..b249a346d6
--- /dev/null
+++ b/browser/components/screenshots/tests/browser/browser_test_resize.js
@@ -0,0 +1,100 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+const windowWidth = 768;
+
+add_task(async function test_window_resize() {
+  await BrowserTestUtils.withNewTab(
+    {
+      gBrowser,
+      url: RESIZE_TEST_PAGE,
+    },
+    async browser => {
+      let helper = new ScreenshotsHelper(browser);
+      await helper.resizeContentWindow(windowWidth, window.outerHeight);
+      const originalContentDimensions = await helper.getContentDimensions();
+      info(JSON.stringify(originalContentDimensions, null, 2));
+
+      await helper.zoomBrowser(1.5);
+
+      helper.triggerUIFromToolbar();
+      await helper.waitForOverlay();
+
+      await helper.scrollContentWindow(windowWidth, window.outerHeight);
+
+      await helper.clickTestPageElement("hello");
+
+      await helper.zoomBrowser(1);
+
+      await helper.waitForOverlaySizeChangeTo(
+        originalContentDimensions.scrollWidth,
+        originalContentDimensions.scrollHeight
+      );
+
+      let contentDims = await helper.getContentDimensions();
+      info(JSON.stringify(contentDims, null, 2));
+
+      is(
+        contentDims.scrollWidth,
+        originalContentDimensions.scrollWidth,
+        "Width of page is back to original"
+      );
+      is(
+        contentDims.scrollHeight,
+        originalContentDimensions.scrollHeight,
+        "Height of page is back to original"
+      );
+    }
+  );
+});
+
+add_task(async function test_window_resize_vertical_writing_mode() {
+  await BrowserTestUtils.withNewTab(
+    {
+      gBrowser,
+      url: RESIZE_TEST_PAGE,
+    },
+    async browser => {
+      await SpecialPowers.spawn(browser, [], () => {
+        content.document.documentElement.style = "writing-mode: vertical-lr;";
+      });
+
+      let helper = new ScreenshotsHelper(browser);
+      await helper.resizeContentWindow(windowWidth, window.outerHeight);
+      const originalContentDimensions = await helper.getContentDimensions();
+      info(JSON.stringify(originalContentDimensions, null, 2));
+
+      await helper.zoomBrowser(1.5);
+
+      helper.triggerUIFromToolbar();
+      await helper.waitForOverlay();
+
+      await helper.scrollContentWindow(windowWidth, window.outerHeight);
+
+      await helper.clickTestPageElement("hello");
+
+      await helper.zoomBrowser(1);
+
+      await helper.waitForOverlaySizeChangeTo(
+        originalContentDimensions.scrollWidth,
+        originalContentDimensions.scrollHeight
+      );
+
+      let contentDims = await helper.getContentDimensions();
+      info(JSON.stringify(contentDims, null, 2));
+
+      is(
+        contentDims.scrollWidth,
+        originalContentDimensions.scrollWidth,
+        "Width of page is back to original"
+      );
+      is(
+        contentDims.scrollHeight,
+        originalContentDimensions.scrollHeight,
+        "Height of page is back to original"
+      );
+    }
+  );
+});
diff --git a/browser/components/screenshots/tests/browser/first-iframe.html b/browser/components/screenshots/tests/browser/first-iframe.html
new file mode 100644
index 0000000000..9b0c123486
--- /dev/null
+++ b/browser/components/screenshots/tests/browser/first-iframe.html
@@ -0,0 +1,23 @@
+<!DOCTYPE HTML>
+<html lang="en">
+  <head>
+    <meta charset="utf-8">
+    <style>
+      div {
+        font-size: 40px;
+        margin: 30px;
+        width: 234px;
+        height: 51px;
+        color: blue;
+      }
+      </style>
+  </head>
+<body>
+  <div>Hello world!</div>
+  <iframe
+    width="300"
+    height="300"
+    src="https://example.org/browser/browser/components/screenshots/tests/browser/second-iframe.html"
+  ></iframe>
+</body>
+</html>
diff --git a/browser/components/screenshots/tests/browser/head.js b/browser/components/screenshots/tests/browser/head.js
new file mode 100644
index 0000000000..171e3b8c41
--- /dev/null
+++ b/browser/components/screenshots/tests/browser/head.js
@@ -0,0 +1,951 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+const { TelemetryTestUtils } = ChromeUtils.importESModule(
+  "resource://testing-common/TelemetryTestUtils.sys.mjs"
+);
+const { UrlbarTestUtils } = ChromeUtils.importESModule(
+  "resource://testing-common/UrlbarTestUtils.sys.mjs"
+);
+
+const TEST_ROOT = getRootDirectory(gTestPath).replace(
+  "chrome://mochitests/content",
+  "https://example.com"
+);
+
+const TEST_PAGE = TEST_ROOT + "test-page.html";
+const SHORT_TEST_PAGE = TEST_ROOT + "short-test-page.html";
+const LARGE_TEST_PAGE = TEST_ROOT + "large-test-page.html";
+const IFRAME_TEST_PAGE = TEST_ROOT + "iframe-test-page.html";
+const RESIZE_TEST_PAGE = TEST_ROOT + "test-page-resize.html";
+
+const { MAX_CAPTURE_DIMENSION, MAX_CAPTURE_AREA } = ChromeUtils.importESModule(
+  "resource:///modules/ScreenshotsUtils.sys.mjs"
+);
+
+const gScreenshotUISelectors = {
+  panel: "#screenshotsPagePanel",
+  fullPageButton: "button.full-page",
+  visiblePageButton: "button.visible-page",
+  copyButton: "button.#copy",
+};
+
+// MouseEvents is for the mouse events on the Anonymous content
+const MouseEvents = {
+  mouse: new Proxy(
+    {},
+    {
+      get: (target, name) =>
+        async function (x, y, options = {}) {
+          if (name === "click") {
+            this.down(x, y, options);
+            this.up(x, y, options);
+          } else {
+            await safeSynthesizeMouseEventInContentPage(":root", x, y, {
+              type: "mouse" + name,
+              ...options,
+            });
+          }
+        },
+    }
+  ),
+};
+
+const { mouse } = MouseEvents;
+
+class ScreenshotsHelper {
+  constructor(browser) {
+    this.browser = browser;
+    this.selector = gScreenshotUISelectors;
+  }
+
+  get toolbarButton() {
+    return this.browser.ownerDocument.getElementById("screenshot-button");
+  }
+
+  get panel() {
+    return this.browser.ownerDocument.querySelector(this.selector.panel);
+  }
+
+  /**
+   * Click the screenshots button in the toolbar
+   */
+  triggerUIFromToolbar() {
+    let button = this.toolbarButton;
+    ok(
+      BrowserTestUtils.isVisible(button),
+      "The screenshot toolbar button is visible"
+    );
+    button.click();
+  }
+
+  async getPanelButton(selector) {
+    let panel = await this.waitForPanel();
+    let screenshotsButtons = panel.querySelector("screenshots-buttons");
+    ok(screenshotsButtons, "Found the screenshots-buttons");
+    let button = screenshotsButtons.shadowRoot.querySelector(selector);
+    ok(button, `Found ${selector} button`);
+    return button;
+  }
+
+  async waitForPanel() {
+    let panel = this.panel;
+    await BrowserTestUtils.waitForCondition(async () => {
+      if (!panel) {
+        panel = this.panel;
+      }
+      return panel && BrowserTestUtils.isVisible(panel);
+    });
+    return panel;
+  }
+
+  async waitForOverlay() {
+    const panel = await this.waitForPanel();
+    ok(BrowserTestUtils.isVisible(panel), "Panel buttons are visible");
+
+    await BrowserTestUtils.waitForCondition(async () => {
+      let init = await this.isOverlayInitialized();
+      return init;
+    });
+    info("Overlay is visible");
+  }
+
+  async waitForPanelClosed() {
+    let panel = this.panel;
+    if (!panel) {
+      info("waitForPanelClosed: Panel doesnt exist");
+      return;
+    }
+    if (panel.hidden) {
+      info("waitForPanelClosed: panel is already hidden");
+      return;
+    }
+    info("waitForPanelClosed: waiting for the panel to become hidden");
+    await BrowserTestUtils.waitForMutationCondition(
+      panel,
+      { attributes: true },
+      () => {
+        return BrowserTestUtils.isHidden(panel);
+      }
+    );
+    ok(BrowserTestUtils.isHidden(panel), "Panel buttons are hidden");
+    info("waitForPanelClosed, panel is hidden: " + panel.hidden);
+  }
+
+  async waitForOverlayClosed() {
+    await this.waitForPanelClosed();
+    await BrowserTestUtils.waitForCondition(async () => {
+      let init = !(await this.isOverlayInitialized());
+      info("Is overlay initialized: " + !init);
+      return init;
+    });
+    info("Overlay is not visible");
+  }
+
+  async isOverlayInitialized() {
+    return SpecialPowers.spawn(this.browser, [], () => {
+      let screenshotsChild = content.windowGlobalChild.getActor(
+        "ScreenshotsComponent"
+      );
+      return screenshotsChild?.overlay?.initialized;
+    });
+  }
+
+  waitForStateChange(newState) {
+    return SpecialPowers.spawn(this.browser, [newState], async state => {
+      let screenshotsChild = content.windowGlobalChild.getActor(
+        "ScreenshotsComponent"
+      );
+
+      await ContentTaskUtils.waitForCondition(() => {
+        info(`got ${screenshotsChild.overlay.state}. expected ${state}`);
+        return screenshotsChild.overlay.state === state;
+      }, `Wait for overlay state to be ${state}`);
+
+      return screenshotsChild.overlay.state;
+    });
+  }
+
+  async assertStateChange(newState) {
+    let currentState = await this.waitForStateChange(newState);
+
+    is(
+      currentState,
+      newState,
+      `The current state is ${currentState}, expected ${newState}`
+    );
+  }
+
+  getHoverElementRect() {
+    return ContentTask.spawn(this.browser, null, async () => {
+      let screenshotsChild = content.windowGlobalChild.getActor(
+        "ScreenshotsComponent"
+      );
+      return screenshotsChild.overlay.hoverElementRegion.dimensions;
+    });
+  }
+
+  isHoverElementRegionValid() {
+    return ContentTask.spawn(this.browser, null, async () => {
+      let screenshotsChild = content.windowGlobalChild.getActor(
+        "ScreenshotsComponent"
+      );
+      return screenshotsChild.overlay.hoverElementRegion.isRegionValid;
+    });
+  }
+
+  async waitForHoverElementRect(expectedWidth, expectedHeight) {
+    return SpecialPowers.spawn(
+      this.browser,
+      [expectedWidth, expectedHeight],
+      async (width, height) => {
+        let screenshotsChild = content.windowGlobalChild.getActor(
+          "ScreenshotsComponent"
+        );
+        let dimensions;
+        await ContentTaskUtils.waitForCondition(() => {
+          dimensions = screenshotsChild.overlay.hoverElementRegion.dimensions;
+          return dimensions.width === width && dimensions.height === height;
+        }, "The hover element region is the expected width and height");
+        return dimensions;
+      }
+    );
+  }
+
+  async waitForSelectionRegionSizeChange(currentWidth) {
+    await ContentTask.spawn(
+      this.browser,
+      [currentWidth],
+      async ([currWidth]) => {
+        let screenshotsChild = content.windowGlobalChild.getActor(
+          "ScreenshotsComponent"
+        );
+
+        let dimensions = screenshotsChild.overlay.selectionRegion.dimensions;
+        await ContentTaskUtils.waitForCondition(() => {
+          dimensions = screenshotsChild.overlay.selectionRegion.dimensions;
+          return dimensions.width !== currWidth;
+        }, "Wait for selection box width change");
+      }
+    );
+  }
+
+  /**
+   * This will drag an overlay starting at the given startX and startY coordinates and ending
+   * at the given endX and endY coordinates.
+   *
+   * endY should be at least 70px from the bottom of window and endX should be at least
+   * 265px from the left of the window. If these requirements are not met then the
+   * overlay buttons (cancel, copy, download) will be positioned different from the default
+   * and the methods to click the overlay buttons will not work unless the updated
+   * position coordinates are supplied.
+   * See https://searchfox.org/mozilla-central/rev/af78418c4b5f2c8721d1a06486cf4cf0b33e1e8d/browser/components/screenshots/ScreenshotsOverlayChild.sys.mjs#1789,1798
+   * for how the overlay buttons are positioned when the overlay rect is near the bottom or
+   * left edge of the window.
+   *
+   * Note: The distance of the rect should be greater than 40 to enter in the "dragging" state.
+   * See https://searchfox.org/mozilla-central/rev/af78418c4b5f2c8721d1a06486cf4cf0b33e1e8d/browser/components/screenshots/ScreenshotsOverlayChild.sys.mjs#809
+   * @param {Number} startX The starting X coordinate. The left edge of the overlay rect.
+   * @param {Number} startY The starting Y coordinate. The top edge of the overlay rect.
+   * @param {Number} endX The end X coordinate. The right edge of the overlay rect.
+   * @param {Number} endY The end Y coordinate. The bottom edge of the overlay rect.
+   */
+  async dragOverlay(
+    startX,
+    startY,
+    endX,
+    endY,
+    expectedStartingState = "crosshairs"
+  ) {
+    await this.assertStateChange(expectedStartingState);
+
+    mouse.down(startX, startY);
+
+    await Promise.any([
+      this.waitForStateChange("draggingReady"),
+      this.waitForStateChange("resizing"),
+    ]);
+    Assert.ok(true, "The overlay is in the draggingReady or resizing state");
+
+    mouse.move(endX, endY);
+
+    await Promise.any([
+      this.waitForStateChange("dragging"),
+      this.waitForStateChange("resizing"),
+    ]);
+    Assert.ok(true, "The overlay is in the dragging or resizing state");
+
+    mouse.up(endX, endY);
+
+    await this.assertStateChange("selected");
+
+    this.endX = endX;
+    this.endY = endY;
+  }
+
+  async moveOverlayViaKeyboard(mover, events) {
+    await SpecialPowers.spawn(
+      this.browser,
+      [mover, events],
+      async (moverToFocus, eventsArr) => {
+        let screenshotsChild = content.windowGlobalChild.getActor(
+          "ScreenshotsComponent"
+        );
+
+        let overlay = screenshotsChild.overlay;
+
+        switch (moverToFocus) {
+          case "highlight":
+            overlay.highlightEl.focus({ focusVisible: true });
+            break;
+          case "mover-bottomLeft":
+            overlay.bottomLeftMover.focus({ focusVisible: true });
+            break;
+          case "mover-bottomRight":
+            overlay.bottomRightMover.focus({ focusVisible: true });
+            break;
+          case "mover-topLeft":
+            overlay.topLeftMover.focus({ focusVisible: true });
+            break;
+          case "mover-topRight":
+            overlay.topRightMover.focus({ focusVisible: true });
+            break;
+        }
+        screenshotsChild.overlay.highlightEl.focus();
+
+        for (let event of eventsArr) {
+          EventUtils.synthesizeKey(
+            event.key,
+            { type: "keydown", ...event.options },
+            content
+          );
+
+          await ContentTaskUtils.waitForCondition(
+            () => overlay.state === "resizing",
+            "Wait for overlay state to be resizing"
+          );
+
+          EventUtils.synthesizeKey(
+            event.key,
+            { type: "keyup", ...event.options },
+            content
+          );
+
+          await ContentTaskUtils.waitForCondition(
+            () => overlay.state === "selected",
+            "Wait for overlay state to be selected"
+          );
+        }
+      }
+    );
+  }
+
+  async scrollContentWindow(x, y) {
+    let promise = BrowserTestUtils.waitForContentEvent(this.browser, "scroll");
+    let contentDims = await this.getContentDimensions();
+    await ContentTask.spawn(
+      this.browser,
+      [x, y, contentDims],
+      async ([xPos, yPos, cDims]) => {
+        content.window.scroll(xPos, yPos);
+
+        info(JSON.stringify(cDims, null, 2));
+        const scrollbarHeight = {};
+        const scrollbarWidth = {};
+        content.window.windowUtils.getScrollbarSize(
+          false,
+          scrollbarWidth,
+          scrollbarHeight
+        );
+
+        await ContentTaskUtils.waitForCondition(() => {
+          function isCloseEnough(a, b, diff) {
+            return Math.abs(a - b) <= diff;
+          }
+
+          info(
+            `scrollbarWidth: ${scrollbarWidth.value}, scrollbarHeight: ${scrollbarHeight.value}`
+          );
+          info(
+            `scrollX: ${content.window.scrollX}, scrollY: ${content.window.scrollY}, scrollMaxX: ${content.window.scrollMaxX}, scrollMaxY: ${content.window.scrollMaxY}`
+          );
+
+          // Sometimes (read intermittently) the scroll width/height will be
+          // off by the width/height of the scrollbar when we are expecting the
+          // page to be scrolled to the very end. To mitigate this, we check
+          // that the below differences are within the scrollbar width/height.
+          return (
+            (content.window.scrollX === xPos ||
+              isCloseEnough(
+                cDims.clientWidth + content.window.scrollX,
+                cDims.scrollWidth,
+                scrollbarWidth.value + 1
+              )) &&
+            (content.window.scrollY === yPos ||
+              isCloseEnough(
+                cDims.clientHeight + content.window.scrollY,
+                cDims.scrollHeight,
+                scrollbarHeight.value + 1
+              ))
+          );
+        }, `Waiting for window to scroll to ${xPos}, ${yPos}`);
+      }
+    );
+    await promise;
+  }
+
+  async waitForScrollTo(x, y) {
+    await ContentTask.spawn(this.browser, [x, y], async ([xPos, yPos]) => {
+      await ContentTaskUtils.waitForCondition(() => {
+        info(
+          `Got scrollX: ${content.window.scrollX}. scrollY: ${content.window.scrollY}`
+        );
+        return (
+          content.window.scrollX === xPos && content.window.scrollY === yPos
+        );
+      }, `Waiting for window to scroll to ${xPos}, ${yPos}`);
+    });
+  }
+
+  async resizeContentWindow(width, height) {
+    this.browser.ownerGlobal.resizeTo(width, height);
+    await TestUtils.waitForCondition(
+      () => window.outerHeight === height && window.outerWidth === width,
+      "Waiting for window to resize"
+    );
+  }
+
+  async clickDownloadButton() {
+    let { centerX: x, centerY: y } = await ContentTask.spawn(
+      this.browser,
+      null,
+      async () => {
+        let screenshotsChild = content.windowGlobalChild.getActor(
+          "ScreenshotsComponent"
+        );
+        let { left, top, width, height } =
+          screenshotsChild.overlay.downloadButton.getBoundingClientRect();
+        let centerX = left + width / 2;
+        let centerY = top + height / 2;
+        return { centerX, centerY };
+      }
+    );
+
+    info(`clicking download button at ${x}, ${y}`);
+    mouse.click(x, y);
+  }
+
+  async clickCopyButton() {
+    let { centerX: x, centerY: y } = await ContentTask.spawn(
+      this.browser,
+      null,
+      async () => {
+        let screenshotsChild = content.windowGlobalChild.getActor(
+          "ScreenshotsComponent"
+        );
+        let { left, top, width, height } =
+          screenshotsChild.overlay.copyButton.getBoundingClientRect();
+        let centerX = left + width / 2;
+        let centerY = top + height / 2;
+        return { centerX, centerY };
+      }
+    );
+
+    info(`clicking copy button at ${x}, ${y}`);
+    mouse.click(x, y);
+  }
+
+  async clickCancelButton() {
+    let { centerX: x, centerY: y } = await ContentTask.spawn(
+      this.browser,
+      null,
+      async () => {
+        let screenshotsChild = content.windowGlobalChild.getActor(
+          "ScreenshotsComponent"
+        );
+        let { left, top, width, height } =
+          screenshotsChild.overlay.cancelButton.getBoundingClientRect();
+        let centerX = left + width / 2;
+        let centerY = top + height / 2;
+        return { centerX, centerY };
+      }
+    );
+
+    info(`clicking cancel button at ${x}, ${y}`);
+    mouse.click(x, y);
+  }
+
+  async clickPreviewCancelButton() {
+    let { centerX: x, centerY: y } = await ContentTask.spawn(
+      this.browser,
+      null,
+      async () => {
+        let screenshotsChild = content.windowGlobalChild.getActor(
+          "ScreenshotsComponent"
+        );
+        let { left, top, width, height } =
+          screenshotsChild.overlay.previewCancelButton.getBoundingClientRect();
+        let centerX = left + width / 2;
+        let centerY = top + height / 2;
+        return { centerX, centerY };
+      }
+    );
+
+    info(`clicking cancel button at ${x}, ${y}`);
+    mouse.click(x, y);
+  }
+
+  escapeKeyInContent() {
+    return SpecialPowers.spawn(this.browser, [], () => {
+      EventUtils.synthesizeKey("KEY_Escape", {}, content);
+    });
+  }
+
+  getTestPageElementRect(elementId = "testPageElement") {
+    return ContentTask.spawn(this.browser, [elementId], async id => {
+      let ele = content.document.getElementById(id);
+      return ele.getBoundingClientRect();
+    });
+  }
+
+  async clickTestPageElement(elementId = "testPageElement") {
+    let rect = await this.getTestPageElementRect(elementId);
+    let dims = await this.getContentDimensions();
+
+    let x = Math.floor(rect.x + dims.scrollX + rect.width / 2);
+    let y = Math.floor(rect.y + dims.scrollY + rect.height / 2);
+
+    mouse.move(x, y);
+    await this.waitForHoverElementRect(rect.width, rect.height);
+    mouse.down(x, y);
+    await this.assertStateChange("draggingReady");
+    mouse.up(x, y);
+    await this.assertStateChange("selected");
+  }
+
+  async zoomBrowser(zoom) {
+    let promise = BrowserTestUtils.waitForContentEvent(this.browser, "resize");
+    await SpecialPowers.spawn(this.browser, [zoom], zoomLevel => {
+      const { Layout } = ChromeUtils.importESModule(
+        "chrome://mochitests/content/browser/accessible/tests/browser/Layout.sys.mjs"
+      );
+      Layout.zoomDocument(content.document, zoomLevel);
+    });
+    await promise;
+  }
+
+  /**
+   * Gets the dialog box
+   * @returns The dialog box
+   */
+  getDialog() {
+    let currDialogBox = this.browser.tabDialogBox;
+    let manager = currDialogBox.getTabDialogManager();
+    let dialogs = manager.hasDialogs && manager.dialogs;
+    return dialogs[0];
+  }
+
+  assertPanelVisible() {
+    info("assertPanelVisible, panel.hidden:" + this.panel?.hidden);
+    Assert.ok(
+      BrowserTestUtils.isVisible(this.panel),
+      "Screenshots panel is visible"
+    );
+  }
+
+  assertPanelNotVisible() {
+    info("assertPanelNotVisible, panel.hidden:" + this.panel?.hidden);
+    Assert.ok(
+      !this.panel || BrowserTestUtils.isHidden(this.panel),
+      "Screenshots panel is not visible"
+    );
+  }
+
+  /**
+   * Copied from screenshots extension
+   * Returns a promise that resolves when the clipboard data has changed
+   * Otherwise rejects
+   */
+  waitForRawClipboardChange(epectedWidth, expectedHeight) {
+    const initialClipboardData = Date.now().toString();
+    SpecialPowers.clipboardCopyString(initialClipboardData);
+
+    return TestUtils.waitForCondition(
+      async () => {
+        let data;
+        try {
+          data = await this.getImageSizeAndColorFromClipboard();
+        } catch (e) {
+          console.log("Failed to get image/png clipboard data:", e);
+          return false;
+        }
+        if (
+          data &&
+          initialClipboardData !== data &&
+          data.height === expectedHeight &&
+          data.width === epectedWidth
+        ) {
+          return data;
+        }
+        return false;
+      },
+      "Waiting for screenshot to copy to clipboard",
+      200
+    );
+  }
+
+  /**
+   * Gets the client and scroll demensions on the window
+   * @returns { Object }
+   *   clientHeight The visible height
+   *   clientWidth The visible width
+   *   scrollHeight The scrollable height
+   *   scrollWidth The scrollable width
+   *   scrollX The scroll x position
+   *   scrollY The scroll y position
+   */
+  getContentDimensions() {
+    return SpecialPowers.spawn(this.browser, [], async function () {
+      let {
+        innerWidth,
+        innerHeight,
+        scrollMaxX,
+        scrollMaxY,
+        scrollX,
+        scrollY,
+      } = content.window;
+      let width = innerWidth + scrollMaxX;
+      let height = innerHeight + scrollMaxY;
+
+      const scrollbarHeight = {};
+      const scrollbarWidth = {};
+      content.window.windowUtils.getScrollbarSize(
+        false,
+        scrollbarWidth,
+        scrollbarHeight
+      );
+      width -= scrollbarWidth.value;
+      height -= scrollbarHeight.value;
+      innerWidth -= scrollbarWidth.value;
+      innerHeight -= scrollbarHeight.value;
+
+      return {
+        clientHeight: innerHeight,
+        clientWidth: innerWidth,
+        scrollHeight: height,
+        scrollWidth: width,
+        scrollX,
+        scrollY,
+      };
+    });
+  }
+
+  async getScreenshotsOverlayDimensions() {
+    return ContentTask.spawn(this.browser, null, async () => {
+      let screenshotsChild = content.windowGlobalChild.getActor(
+        "ScreenshotsComponent"
+      );
+      Assert.ok(screenshotsChild.overlay.initialized, "The overlay exists");
+
+      let screenshotsContainer = screenshotsChild.overlay.screenshotsContainer;
+
+      await ContentTaskUtils.waitForCondition(() => {
+        return !screenshotsContainer.hasAttribute("resizing");
+      }, "Waiting for overlay to be done resizing");
+
+      info(
+        `${screenshotsContainer.style.width} ${
+          screenshotsContainer.style.height
+        } ${screenshotsContainer.hasAttribute("resizing")}`
+      );
+
+      return {
+        scrollWidth: screenshotsContainer.scrollWidth,
+        scrollHeight: screenshotsContainer.scrollHeight,
+      };
+    });
+  }
+
+  async waitForSelectionLayerDimensionChange(oldWidth, oldHeight) {
+    await ContentTask.spawn(
+      this.browser,
+      [oldWidth, oldHeight],
+      async ([prevWidth, prevHeight]) => {
+        let screenshotsChild = content.windowGlobalChild.getActor(
+          "ScreenshotsComponent"
+        );
+
+        await ContentTaskUtils.waitForCondition(() => {
+          let screenshotsContainer =
+            screenshotsChild.overlay.screenshotsContainer;
+          info(
+            `old height: ${prevHeight}. new height: ${screenshotsContainer.scrollHeight}.\nold width: ${prevWidth}. new width: ${screenshotsContainer.scrollWidth}`
+          );
+          return (
+            screenshotsContainer.scrollHeight !== prevHeight &&
+            screenshotsContainer.scrollWidth !== prevWidth
+          );
+        }, "Wait for selection box width change");
+      }
+    );
+  }
+
+  waitForOverlaySizeChangeTo(width, height) {
+    return ContentTask.spawn(
+      this.browser,
+      [width, height],
+      async ([newWidth, newHeight]) => {
+        await ContentTaskUtils.waitForCondition(() => {
+          let {
+            innerHeight,
+            innerWidth,
+            scrollMaxY,
+            scrollMaxX,
+            scrollMinY,
+            scrollMinX,
+          } = content.window;
+          let scrollWidth = innerWidth + scrollMaxX - scrollMinX;
+          let scrollHeight = innerHeight + scrollMaxY - scrollMinY;
+
+          const scrollbarHeight = {};
+          const scrollbarWidth = {};
+          content.window.windowUtils.getScrollbarSize(
+            false,
+            scrollbarWidth,
+            scrollbarHeight
+          );
+          scrollWidth -= scrollbarWidth.value;
+          scrollHeight -= scrollbarHeight.value;
+          info(
+            `${scrollHeight}, ${newHeight}, ${scrollWidth}, ${newWidth}, ${content.window.scrollMaxX}`
+          );
+          return scrollHeight === newHeight && scrollWidth === newWidth;
+        }, "Wait for document size change");
+      }
+    );
+  }
+
+  getSelectionRegionDimensions() {
+    return ContentTask.spawn(this.browser, null, async () => {
+      let screenshotsChild = content.windowGlobalChild.getActor(
+        "ScreenshotsComponent"
+      );
+      Assert.ok(screenshotsChild.overlay.initialized, "The overlay exists");
+
+      return screenshotsChild.overlay.selectionRegion.dimensions;
+    });
+  }
+
+  /**
+   * Copied from screenshots extension
+   * A helper that returns the size of the image that was just put into the clipboard by the
+   * :screenshot command.
+   * @return The {width, height, color} dimension and color object.
+   */
+  async getImageSizeAndColorFromClipboard() {
+    let flavor = "image/png";
+    let image = getRawClipboardData(flavor);
+    if (!image) {
+      return false;
+    }
+
+    // Due to the differences in how images could be stored in the clipboard the
+    // checks below are needed. The clipboard could already provide the image as
+    // byte streams or as image container. If it's not possible obtain a
+    // byte stream, the function throws.
+
+    if (image instanceof Ci.imgIContainer) {
+      image = Cc["@mozilla.org/image/tools;1"]
+        .getService(Ci.imgITools)
+        .encodeImage(image, flavor);
+    }
+
+    if (!(image instanceof Ci.nsIInputStream)) {
+      throw new Error("Unable to read image data");
+    }
+
+    const binaryStream = Cc["@mozilla.org/binaryinputstream;1"].createInstance(
+      Ci.nsIBinaryInputStream
+    );
+    binaryStream.setInputStream(image);
+    const available = binaryStream.available();
+    const buffer = new ArrayBuffer(available);
+    info(
+      `${binaryStream.readArrayBuffer(
+        available,
+        buffer
+      )} read, ${available} available`
+    );
+
+    // We are going to load the image in the content page to measure its size.
+    // We don't want to insert the image directly in the browser's document
+    // which could mess all sorts of things up
+    return SpecialPowers.spawn(
+      this.browser,
+      [buffer],
+      async function (_buffer) {
+        const img = content.document.createElement("img");
+        const loaded = new Promise(r => {
+          img.addEventListener("load", r, { once: true });
+        });
+        const url = content.URL.createObjectURL(
+          new Blob([_buffer], { type: "image/png" })
+        );
+
+        img.src = url;
+        content.document.documentElement.appendChild(img);
+
+        info("Waiting for the clipboard image to load in the content page");
+        await loaded;
+
+        let canvas = content.document.createElementNS(
+          "http://www.w3.org/1999/xhtml",
+          "html:canvas"
+        );
+        let context = canvas.getContext("2d");
+        canvas.width = img.width;
+        canvas.height = img.height;
+        context.drawImage(img, 0, 0);
+        let topLeft = context.getImageData(0, 0, 1, 1);
+        let topRight = context.getImageData(img.width - 1, 0, 1, 1);
+        let bottomLeft = context.getImageData(0, img.height - 1, 1, 1);
+        let bottomRight = context.getImageData(
+          img.width - 1,
+          img.height - 1,
+          1,
+          1
+        );
+
+        img.remove();
+        content.URL.revokeObjectURL(url);
+
+        return {
+          width: img.width,
+          height: img.height,
+          color: {
+            topLeft: topLeft.data,
+            topRight: topRight.data,
+            bottomLeft: bottomLeft.data,
+            bottomRight: bottomRight.data,
+          },
+        };
+      }
+    );
+  }
+}
+
+/**
+ * Get the raw clipboard data
+ * @param flavor Type of data to get from clipboard
+ * @returns The data from the clipboard
+ */
+function getRawClipboardData(flavor) {
+  const whichClipboard = Services.clipboard.kGlobalClipboard;
+  const xferable = Cc["@mozilla.org/widget/transferable;1"].createInstance(
+    Ci.nsITransferable
+  );
+  xferable.init(null);
+  xferable.addDataFlavor(flavor);
+  Services.clipboard.getData(
+    xferable,
+    whichClipboard,
+    SpecialPowers.wrap(window).browsingContext.currentWindowContext
+  );
+  let data = {};
+  try {
+    // xferable.getTransferData(flavor, data);
+    xferable.getAnyTransferData({}, data);
+    info(JSON.stringify(data, null, 2));
+  } catch (e) {
+    info(e);
+  }
+  data = data.value || null;
+  return data;
+}
+
+/**
+ * Synthesize a mouse event on an element, after ensuring that it is visible
+ * in the viewport.
+ *
+ * @param {String} selector: The node selector to get the node target for the event.
+ * @param {number} x
+ * @param {number} y
+ * @param {object} options: Options that will be passed to BrowserTestUtils.synthesizeMouse
+ */
+async function safeSynthesizeMouseEventInContentPage(
+  selector,
+  x,
+  y,
+  options = {}
+) {
+  let context = gBrowser.selectedBrowser.browsingContext;
+  BrowserTestUtils.synthesizeMouse(selector, x, y, options, context);
+}
+
+add_setup(async () => {
+  CustomizableUI.addWidgetToArea(
+    "screenshot-button",
+    CustomizableUI.AREA_NAVBAR,
+    0
+  );
+  let screenshotBtn = document.getElementById("screenshot-button");
+  Assert.ok(screenshotBtn, "The screenshots button was added to the nav bar");
+});
+
+function getContentDevicePixelRatio(browser) {
+  return SpecialPowers.spawn(browser, [], async function () {
+    return content.window.devicePixelRatio;
+  });
+}
+
+async function clearAllTelemetryEvents() {
+  // Clear everything.
+  info("Clearing all telemetry events");
+  await TestUtils.waitForCondition(() => {
+    Services.telemetry.clearEvents();
+    let events = Services.telemetry.snapshotEvents(
+      Ci.nsITelemetry.DATASET_PRERELEASE_CHANNELS,
+      true
+    );
+    let content = events.content;
+    let parent = events.parent;
+
+    return (!content && !parent) || (!content.length && !parent.length);
+  });
+}
+
+async function waitForScreenshotsEventCount(count, process = "parent") {
+  await TestUtils.waitForCondition(
+    () => {
+      let events = TelemetryTestUtils.getEvents(
+        { category: "screenshots" },
+        { process }
+      );
+
+      info(`Got ${events?.length} event(s)`);
+      info(`Actual events: ${JSON.stringify(events, null, 2)}`);
+      return events.length === count ? events : null;
+    },
+    `Waiting for ${count} ${process} event(s).`,
+    200,
+    100
+  );
+}
+
+async function assertScreenshotsEvents(
+  expectedEvents,
+  process = "parent",
+  clearEvents = true
+) {
+  info(`Expected events: ${JSON.stringify(expectedEvents, null, 2)}`);
+  // Make sure we have recorded the correct number of events
+  await waitForScreenshotsEventCount(expectedEvents.length, process);
+
+  TelemetryTestUtils.assertEvents(
+    expectedEvents,
+    { category: "screenshots" },
+    { clear: clearEvents, process }
+  );
+}
diff --git a/browser/components/screenshots/tests/browser/iframe-test-page.html b/browser/components/screenshots/tests/browser/iframe-test-page.html
new file mode 100644
index 0000000000..5439552734
--- /dev/null
+++ b/browser/components/screenshots/tests/browser/iframe-test-page.html
@@ -0,0 +1,23 @@
+<!DOCTYPE HTML>
+<html lang="en">
+  <head>
+    <title>Screenshots</title>
+    <style>
+      div {
+        font-size: 40px;
+        margin: 30px;
+        width: 233px;
+        height: 50px;
+        color: green;
+      }
+    </style>
+  </head>
+  <body>
+    <div>Hello world!</div>
+    <iframe
+      width="500"
+      height="500"
+      src="https://example.com/browser/browser/components/screenshots/tests/browser/first-iframe.html"
+    ></iframe>
+  </body>
+</html>
diff --git a/browser/components/screenshots/tests/browser/large-test-page.html b/browser/components/screenshots/tests/browser/large-test-page.html
new file mode 100644
index 0000000000..ab2eb8d601
--- /dev/null
+++ b/browser/components/screenshots/tests/browser/large-test-page.html
@@ -0,0 +1,9 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+    <meta charset="UTF-8">
+    <title>Screenshots</title>
+</head>
+<body style="height:40000px; width:40000px; background-repeat: no-repeat; background-size: 40008px 40016px; background-color: rgb(111, 111, 111); background-image:linear-gradient(to right, transparent 50%, rgba(0, 200, 200, 0.5) 50%),linear-gradient(to bottom, transparent 50%, rgba(100, 0, 100, 0.5) 50%);">
+</body>
+</html>
diff --git a/browser/components/screenshots/tests/browser/second-iframe.html b/browser/components/screenshots/tests/browser/second-iframe.html
new file mode 100644
index 0000000000..ca5de26bb9
--- /dev/null
+++ b/browser/components/screenshots/tests/browser/second-iframe.html
@@ -0,0 +1,18 @@
+<!DOCTYPE HTML>
+<html lang="en">
+  <head>
+    <meta charset="utf-8">
+    <style>
+      div {
+        font-size: 40px;
+        margin: 30px;
+        width: 235px;
+        height: 52px;
+        color: red;
+      }
+    </style>
+  </head>
+<body>
+  <div>Hello world!</div>
+</body>
+</html>
diff --git a/browser/components/screenshots/tests/browser/short-test-page.html b/browser/components/screenshots/tests/browser/short-test-page.html
new file mode 100644
index 0000000000..7718892f8c
--- /dev/null
+++ b/browser/components/screenshots/tests/browser/short-test-page.html
@@ -0,0 +1,8 @@
+<html lang="en">
+<head>
+  <title>Screenshots</title>
+</head>
+<body>
+  <div style="height:500px; width:500px; background-color: blue;"></div>
+</body>
+</html>
diff --git a/browser/components/screenshots/tests/browser/test-page-resize.html b/browser/components/screenshots/tests/browser/test-page-resize.html
new file mode 100644
index 0000000000..dea57909b4
--- /dev/null
+++ b/browser/components/screenshots/tests/browser/test-page-resize.html
@@ -0,0 +1,25 @@
+<html>
+<head>
+  <title>Screenshots</title>
+</head>
+<body>
+  <div style="display: flex;flex-flow: row wrap;gap: 8px;">
+    <div style="height:100px; width:100px; background-color: blue;"></div>
+    <div style="height:100px; width:100px; background-color: blue;"></div>
+    <div style="height:100px; width:100px; background-color: blue;"></div>
+    <div style="height:100px; width:100px; background-color: blue;"></div>
+    <div style="height:100px; width:100px; background-color: blue;"></div>
+    <div style="height:100px; width:100px; background-color: blue;"></div>
+  </div>
+  <div style="display: flex;flex-direction: column;gap: 8px;">
+    <div style="height:100px; width:100px; background-color: red;"></div>
+    <div style="height:100px; width:100px; background-color: red;"></div>
+    <div style="height:100px; width:100px; background-color: red;"></div>
+    <div style="height:100px; width:100px; background-color: red;"></div>
+    <div style="height:100px; width:100px; background-color: red;"></div>
+    <div style="height:100px; width:100px; background-color: red;"></div>
+    <div style="height:100px; width:100px; background-color: red;"></div>
+    <div id="hello" style="height:100px; width:100px; background-color: red;"></div>
+  </div>
+</body>
+</html>
diff --git a/browser/components/screenshots/tests/browser/test-page.html b/browser/components/screenshots/tests/browser/test-page.html
new file mode 100644
index 0000000000..5ddc1d6eb6
--- /dev/null
+++ b/browser/components/screenshots/tests/browser/test-page.html
@@ -0,0 +1,27 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+    <meta charset="UTF-8">
+    <title>Screenshots</title>
+</head>
+<body style="height:4000px; width:4000px; background-repeat: no-repeat; background-size: 4008px 4016px; background-color: rgb(111, 111, 111); background-image:linear-gradient(to right, transparent 50%, rgba(0, 200, 200, 0.5) 50%),linear-gradient(to bottom, transparent 50%, rgba(100, 0, 100, 0.5) 50%);">
+    <div id="testPageElement" style="position:absolute; top:91px; left:93px; width:92px; height:94px; border:solid red;"></div>
+    <script>
+        // Make sure the screenshots overlay anonymous document always receives events
+        // that web content would normally be able to intercept, as that could break the
+        // overlay
+        function disabledEvent(event) {
+            event.preventDefault();
+            event.stopImmediatePropagation();
+        }
+
+        window.addEventListener("click", disabledEvent, true);
+        window.addEventListener("pointerdown", disabledEvent, true);
+        window.addEventListener("pointermove", disabledEvent, true);
+        window.addEventListener("mousemove", disabledEvent, true);
+        window.addEventListener("pointerup", disabledEvent, true);
+        window.addEventListener("keydown", disabledEvent, true);
+        window.addEventListener("keyup", disabledEvent, true);
+    </script>
+</body>
+</html>