Merging upstream version 115.11.0esr.

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

14 files changed, 142 insertions, 470 deletions

diff --git a/browser/components/sessionstore/test/browser.ini b/browser/components/sessionstore/test/browser.ini
index 85e0c40448..a282c6f268 100644
--- a/browser/components/sessionstore/test/browser.ini
+++ b/browser/components/sessionstore/test/browser.ini
@@ -218,7 +218,6 @@ support-files = file_async_duplicate_tab.html
 support-files = file_async_flushes.html
 run-if = crashreporter
 [browser_async_remove_tab.js]
-skip-if = !sessionHistoryInParent
 [browser_async_window_flushing.js]
 https_first_disabled = true
 skip-if =
@@ -319,7 +318,6 @@ skip-if =
   ccov # Bug 1625525
 [browser_privatetabs.js]
 [browser_purge_shistory.js]
-skip-if = !sessionHistoryInParent # Bug 1271024
 [browser_remoteness_flip_on_restore.js]
 [browser_reopen_all_windows.js]
 https_first_disabled = true
@@ -348,8 +346,6 @@ skip-if =
   !fission
   os == "linux" # Bug 1716445
 [browser_scrollPositionsReaderMode.js]
-[browser_send_async_message_oom.js]
-skip-if = sessionHistoryInParent # Tests that the frame script OOMs, which is unused when SHIP is enabled.
 [browser_sessionHistory.js]
 https_first_disabled = true
 support-files =
diff --git a/browser/components/sessionstore/test/browser_687710_2.js b/browser/components/sessionstore/test/browser_687710_2.js
index 81d3c55379..190b5a718a 100644
--- a/browser/components/sessionstore/test/browser_687710_2.js
+++ b/browser/components/sessionstore/test/browser_687710_2.js
@@ -38,61 +38,31 @@ var state = {
 add_task(async function test() {
   let tab = BrowserTestUtils.addTab(gBrowser, "about:blank");
   await promiseTabState(tab, state);
-  if (!SpecialPowers.Services.appinfo.sessionHistoryInParent) {
-    await SpecialPowers.spawn(tab.linkedBrowser, [], function () {
-      function compareEntries(i, j, history) {
-        let e1 = history.getEntryAtIndex(i);
-        let e2 = history.getEntryAtIndex(j);
 
-        ok(e1.sharesDocumentWith(e2), `${i} should share doc with ${j}`);
-        is(e1.childCount, e2.childCount, `Child count mismatch (${i}, ${j})`);
+  function compareEntries(i, j, history) {
+    let e1 = history.getEntryAtIndex(i);
+    let e2 = history.getEntryAtIndex(j);
 
-        for (let c = 0; c < e1.childCount; c++) {
-          let c1 = e1.GetChildAt(c);
-          let c2 = e2.GetChildAt(c);
+    ok(e1.sharesDocumentWith(e2), `${i} should share doc with ${j}`);
+    is(e1.childCount, e2.childCount, `Child count mismatch (${i}, ${j})`);
 
-          ok(
-            c1.sharesDocumentWith(c2),
-            `Cousins should share documents. (${i}, ${j}, ${c})`
-          );
-        }
-      }
+    for (let c = 0; c < e1.childCount; c++) {
+      let c1 = e1.GetChildAt(c);
+      let c2 = e2.GetChildAt(c);
 
-      let history = docShell.browsingContext.childSessionHistory.legacySHistory;
-
-      is(history.count, 2, "history.count");
-      for (let i = 0; i < history.count; i++) {
-        for (let j = 0; j < history.count; j++) {
-          compareEntries(i, j, history);
-        }
-      }
-    });
-  } else {
-    function compareEntries(i, j, history) {
-      let e1 = history.getEntryAtIndex(i);
-      let e2 = history.getEntryAtIndex(j);
-
-      ok(e1.sharesDocumentWith(e2), `${i} should share doc with ${j}`);
-      is(e1.childCount, e2.childCount, `Child count mismatch (${i}, ${j})`);
-
-      for (let c = 0; c < e1.childCount; c++) {
-        let c1 = e1.GetChildAt(c);
-        let c2 = e2.GetChildAt(c);
-
-        ok(
-          c1.sharesDocumentWith(c2),
-          `Cousins should share documents. (${i}, ${j}, ${c})`
-        );
-      }
+      ok(
+        c1.sharesDocumentWith(c2),
+        `Cousins should share documents. (${i}, ${j}, ${c})`
+      );
     }
+  }
 
-    let history = tab.linkedBrowser.browsingContext.sessionHistory;
+  let history = tab.linkedBrowser.browsingContext.sessionHistory;
 
-    is(history.count, 2, "history.count");
-    for (let i = 0; i < history.count; i++) {
-      for (let j = 0; j < history.count; j++) {
-        compareEntries(i, j, history);
-      }
+  is(history.count, 2, "history.count");
+  for (let i = 0; i < history.count; i++) {
+    for (let j = 0; j < history.count; j++) {
+      compareEntries(i, j, history);
     }
   }
 
diff --git a/browser/components/sessionstore/test/browser_705597.js b/browser/components/sessionstore/test/browser_705597.js
index d497e46a97..10f4f08863 100644
--- a/browser/components/sessionstore/test/browser_705597.js
+++ b/browser/components/sessionstore/test/browser_705597.js
@@ -26,14 +26,8 @@ function test() {
   let browser = tab.linkedBrowser;
 
   promiseTabState(tab, tabState).then(() => {
-    let entry;
-    if (!Services.appinfo.sessionHistoryInParent) {
-      let sessionHistory = browser.sessionHistory;
-      entry = sessionHistory.legacySHistory.getEntryAtIndex(0);
-    } else {
-      let sessionHistory = browser.browsingContext.sessionHistory;
-      entry = sessionHistory.getEntryAtIndex(0);
-    }
+    let sessionHistory = browser.browsingContext.sessionHistory;
+    let entry = sessionHistory.getEntryAtIndex(0);
 
     whenChildCount(entry, 1, function () {
       whenChildCount(entry, 2, function () {
diff --git a/browser/components/sessionstore/test/browser_707862.js b/browser/components/sessionstore/test/browser_707862.js
index 765c63257f..4559362e21 100644
--- a/browser/components/sessionstore/test/browser_707862.js
+++ b/browser/components/sessionstore/test/browser_707862.js
@@ -26,26 +26,14 @@ function test() {
   let browser = tab.linkedBrowser;
 
   promiseTabState(tab, tabState).then(() => {
-    let entry;
-    if (!Services.appinfo.sessionHistoryInParent) {
-      let sessionHistory = browser.sessionHistory;
-      entry = sessionHistory.legacySHistory.getEntryAtIndex(0);
-    } else {
-      let sessionHistory = browser.browsingContext.sessionHistory;
-      entry = sessionHistory.getEntryAtIndex(0);
-    }
+    let sessionHistory = browser.browsingContext.sessionHistory;
+    let entry = sessionHistory.getEntryAtIndex(0);
 
     whenChildCount(entry, 1, function () {
       whenChildCount(entry, 2, function () {
         promiseBrowserLoaded(browser).then(() => {
-          let newEntry;
-          if (!Services.appinfo.sessionHistoryInParent) {
-            let newSessionHistory = browser.sessionHistory;
-            newEntry = newSessionHistory.legacySHistory.getEntryAtIndex(0);
-          } else {
-            let newSessionHistory = browser.browsingContext.sessionHistory;
-            newEntry = newSessionHistory.getEntryAtIndex(0);
-          }
+          let newSessionHistory = browser.browsingContext.sessionHistory;
+          let newEntry = newSessionHistory.getEntryAtIndex(0);
 
           whenChildCount(newEntry, 0, function () {
             // Make sure that we reset the state.
diff --git a/browser/components/sessionstore/test/browser_async_flushes.js b/browser/components/sessionstore/test/browser_async_flushes.js
index e35593dc30..d0bf039ff2 100644
--- a/browser/components/sessionstore/test/browser_async_flushes.js
+++ b/browser/components/sessionstore/test/browser_async_flushes.js
@@ -44,58 +44,6 @@ add_task(async function test_flush() {
   gBrowser.removeTab(tab);
 });
 
-add_task(async function test_crash() {
-  if (Services.appinfo.sessionHistoryInParent) {
-    // This test relies on frame script message ordering. Since the frame script
-    // is unused with SHIP, there's no guarantee that we'll crash the frame
-    // before we've started the flush.
-    ok(true, "Test relies on frame script message ordering.");
-    return;
-  }
-
-  // Create new tab.
-  let tab = BrowserTestUtils.addTab(gBrowser, URL);
-  gBrowser.selectedTab = tab;
-  let browser = tab.linkedBrowser;
-  await promiseBrowserLoaded(browser);
-
-  // Flush to empty any queued update messages.
-  await TabStateFlusher.flush(browser);
-
-  // There should be one history entry.
-  let { entries } = JSON.parse(ss.getTabState(tab));
-  is(entries.length, 1, "there is a single history entry");
-
-  // Click the link to navigate.
-  await SpecialPowers.spawn(browser, [], async function () {
-    return new Promise(resolve => {
-      docShell.chromeEventHandler.addEventListener(
-        "hashchange",
-        () => resolve(),
-        { once: true, capture: true }
-      );
-
-      // Click the link.
-      content.document.querySelector("a").click();
-    });
-  });
-
-  // Crash the browser and flush. Both messages are async and will be sent to
-  // the content process. The "crash" message makes it first so that we don't
-  // get a chance to process the flush. The TabStateFlusher however should be
-  // notified so that the flush still completes.
-  let promise1 = BrowserTestUtils.crashFrame(browser);
-  let promise2 = TabStateFlusher.flush(browser);
-  await Promise.all([promise1, promise2]);
-
-  // The pending update should be lost.
-  ({ entries } = JSON.parse(ss.getTabState(tab)));
-  is(entries.length, 1, "still only one history entry");
-
-  // Cleanup.
-  gBrowser.removeTab(tab);
-});
-
 add_task(async function test_remove() {
   // Create new tab.
   let tab = BrowserTestUtils.addTab(gBrowser, URL);
diff --git a/browser/components/sessionstore/test/browser_async_remove_tab.js b/browser/components/sessionstore/test/browser_async_remove_tab.js
index 6f744ade3c..28c20512f1 100644
--- a/browser/components/sessionstore/test/browser_async_remove_tab.js
+++ b/browser/components/sessionstore/test/browser_async_remove_tab.js
@@ -92,15 +92,7 @@ add_task(async function save_worthy_tabs_remote_final() {
   ok(browser.isRemoteBrowser, "browser is still remote");
 
   // Remove the tab before the update arrives.
-  let promise = promiseRemoveTabAndSessionState(tab);
-
-  // With SHIP, we'll do the final tab state update sooner than we did before.
-  if (!Services.appinfo.sessionHistoryInParent) {
-    // No tab state worth saving (that we know about yet).
-    ok(!isValueInClosedData(r), "closed tab not saved");
-  }
-
-  await promise;
+  await promiseRemoveTabAndSessionState(tab);
 
   // Turns out there is a tab state worth saving.
   ok(isValueInClosedData(r), "closed tab saved");
@@ -117,15 +109,7 @@ add_task(async function save_worthy_tabs_nonremote_final() {
   ok(!browser.isRemoteBrowser, "browser is not remote anymore");
 
   // Remove the tab before the update arrives.
-  let promise = promiseRemoveTabAndSessionState(tab);
-
-  // With SHIP, we'll do the final tab state update sooner than we did before.
-  if (!Services.appinfo.sessionHistoryInParent) {
-    // No tab state worth saving (that we know about yet).
-    ok(!isValueInClosedData(r), "closed tab not saved");
-  }
-
-  await promise;
+  await promiseRemoveTabAndSessionState(tab);
 
   // Turns out there is a tab state worth saving.
   ok(isValueInClosedData(r), "closed tab saved");
@@ -151,15 +135,7 @@ add_task(async function dont_save_empty_tabs_final() {
   await entryReplaced;
 
   // Remove the tab before the update arrives.
-  let promise = promiseRemoveTabAndSessionState(tab);
-
-  // With SHIP, we'll do the final tab state update sooner than we did before.
-  if (!Services.appinfo.sessionHistoryInParent) {
-    // Tab state deemed worth saving (yet).
-    ok(isValueInClosedData(r), "closed tab saved");
-  }
-
-  await promise;
+  await promiseRemoveTabAndSessionState(tab);
 
   // Turns out we don't want to save the tab state.
   ok(!isValueInClosedData(r), "closed tab not saved");
diff --git a/browser/components/sessionstore/test/browser_async_window_flushing.js b/browser/components/sessionstore/test/browser_async_window_flushing.js
index 56781896d8..56cd3ad1e3 100644
--- a/browser/components/sessionstore/test/browser_async_window_flushing.js
+++ b/browser/components/sessionstore/test/browser_async_window_flushing.js
@@ -116,17 +116,10 @@ add_task(async function test_remove_uninteresting_window() {
   await SpecialPowers.spawn(browser, [], async function () {
     // Epic hackery to make this browser seem suddenly boring.
     docShell.setCurrentURIForSessionStore(Services.io.newURI("about:blank"));
-
-    if (!SpecialPowers.Services.appinfo.sessionHistoryInParent) {
-      let { sessionHistory } = docShell.QueryInterface(Ci.nsIWebNavigation);
-      sessionHistory.legacySHistory.purgeHistory(sessionHistory.count);
-    }
   });
 
-  if (SpecialPowers.Services.appinfo.sessionHistoryInParent) {
-    let { sessionHistory } = browser.browsingContext;
-    sessionHistory.purgeHistory(sessionHistory.count);
-  }
+  let { sessionHistory } = browser.browsingContext;
+  sessionHistory.purgeHistory(sessionHistory.count);
 
   // Once this windowClosed Promise resolves, we should have finished
   // the flush and revisited our decision to put this window into
diff --git a/browser/components/sessionstore/test/browser_attributes.js b/browser/components/sessionstore/test/browser_attributes.js
index 336573a508..db349a31a2 100644
--- a/browser/components/sessionstore/test/browser_attributes.js
+++ b/browser/components/sessionstore/test/browser_attributes.js
@@ -38,45 +38,68 @@ add_task(async function test() {
   ok(tab.hasAttribute("muted"), "tab.muted exists");
 
   // Make sure we do not persist 'image' and 'muted' attributes.
-  ss.persistTabAttribute("image");
-  ss.persistTabAttribute("muted");
   let { attributes } = JSON.parse(ss.getTabState(tab));
   ok(!("image" in attributes), "'image' attribute not saved");
   ok(!("muted" in attributes), "'muted' attribute not saved");
-  ok(!("custom" in attributes), "'custom' attribute not saved");
-
-  // Test persisting a custom attribute.
-  tab.setAttribute("custom", "foobar");
-  ss.persistTabAttribute("custom");
-
-  ({ attributes } = JSON.parse(ss.getTabState(tab)));
-  is(attributes.custom, "foobar", "'custom' attribute is correct");
-
-  // Make sure we're backwards compatible and restore old 'image' attributes.
+  ok(!("customizemode" in attributes), "'customizemode' attribute not saved");
+
+  // Test persisting a customizemode attribute.
+  {
+    let customizationReady = BrowserTestUtils.waitForEvent(
+      gNavToolbox,
+      "customizationready"
+    );
+    gCustomizeMode.enter();
+    await customizationReady;
+  }
+
+  let customizeIcon = gBrowser.getIcon(gBrowser.selectedTab);
+  ({ attributes } = JSON.parse(ss.getTabState(gBrowser.selectedTab)));
+  ok(!("image" in attributes), "'image' attribute not saved");
+  is(attributes.customizemode, "true", "'customizemode' attribute is correct");
+
+  {
+    let afterCustomization = BrowserTestUtils.waitForEvent(
+      gNavToolbox,
+      "aftercustomization"
+    );
+    gCustomizeMode.exit();
+    await afterCustomization;
+  }
+
+  // Test restoring a customizemode tab.
   let state = {
-    entries: [{ url: "about:mozilla", triggeringPrincipal_base64 }],
-    attributes: { custom: "foobaz" },
-    image: gBrowser.getIcon(tab),
+    entries: [],
+    attributes: { customizemode: "true", nonpersisted: "true" },
   };
 
+  // Customize mode doesn't like being restored on top of a non-blank tab.
+  // For the moment, it appears it isn't possible to restore customizemode onto
+  // an existing non-blank tab outside of tests, however this may be a latent
+  // bug if we ever try to do that in the future.
+  let principal = Services.scriptSecurityManager.createNullPrincipal({});
+  tab.linkedBrowser.createAboutBlankContentViewer(principal, principal);
+
   // Prepare a pending tab waiting to be restored.
   let promise = promiseTabRestoring(tab);
   ss.setTabState(tab, JSON.stringify(state));
   await promise;
 
   ok(tab.hasAttribute("pending"), "tab is pending");
-  is(gBrowser.getIcon(tab), state.image, "tab has correct icon");
+  ok(tab.hasAttribute("customizemode"), "tab is in customizemode");
+  ok(!tab.hasAttribute("nonpersisted"), "tab has no nonpersisted attribute");
+  is(gBrowser.getIcon(tab), customizeIcon, "tab has correct icon");
   ok(!state.attributes.image, "'image' attribute not saved");
 
   // Let the pending tab load.
   gBrowser.selectedTab = tab;
-  await promiseTabRestored(tab);
 
   // Ensure no 'image' or 'pending' attributes are stored.
   ({ attributes } = JSON.parse(ss.getTabState(tab)));
   ok(!("image" in attributes), "'image' attribute not saved");
   ok(!("pending" in attributes), "'pending' attribute not saved");
-  is(attributes.custom, "foobaz", "'custom' attribute is correct");
+  ok(!("nonpersisted" in attributes), "'nonpersisted' attribute not saved");
+  is(attributes.customizemode, "true", "'customizemode' attribute is correct");
 
   // Clean up.
   gBrowser.removeTab(tab);
diff --git a/browser/components/sessionstore/test/browser_bfcache_telemetry.js b/browser/components/sessionstore/test/browser_bfcache_telemetry.js
index daa4bcf44e..9e913eb605 100644
--- a/browser/components/sessionstore/test/browser_bfcache_telemetry.js
+++ b/browser/components/sessionstore/test/browser_bfcache_telemetry.js
@@ -39,7 +39,6 @@ async function test_bfcache_telemetry(probeInParent) {
 
 add_task(async () => {
   await test_bfcache_telemetry(
-    Services.appinfo.sessionHistoryInParent &&
-      Services.prefs.getBoolPref("fission.bfcacheInParent")
+    Services.prefs.getBoolPref("fission.bfcacheInParent")
   );
 });
diff --git a/browser/components/sessionstore/test/browser_docshell_uuid_consistency.js b/browser/components/sessionstore/test/browser_docshell_uuid_consistency.js
index 2414e04276..42e7678a92 100644
--- a/browser/components/sessionstore/test/browser_docshell_uuid_consistency.js
+++ b/browser/components/sessionstore/test/browser_docshell_uuid_consistency.js
@@ -4,38 +4,18 @@ add_task(async function duplicateTab() {
   let tab = BrowserTestUtils.addTab(gBrowser, TEST_URL);
   await BrowserTestUtils.browserLoaded(tab.linkedBrowser);
 
-  if (!Services.appinfo.sessionHistoryInParent) {
-    await SpecialPowers.spawn(tab.linkedBrowser, [], function () {
-      let docshell = content.window.docShell.QueryInterface(
-        Ci.nsIWebNavigation
-      );
-      let shEntry = docshell.sessionHistory.legacySHistory.getEntryAtIndex(0);
-      is(shEntry.docshellID.toString(), docshell.historyID.toString());
-    });
-  } else {
-    let historyID = tab.linkedBrowser.browsingContext.historyID;
-    let shEntry =
-      tab.linkedBrowser.browsingContext.sessionHistory.getEntryAtIndex(0);
-    is(shEntry.docshellID.toString(), historyID.toString());
-  }
+  let historyID = tab.linkedBrowser.browsingContext.historyID;
+  let shEntry =
+    tab.linkedBrowser.browsingContext.sessionHistory.getEntryAtIndex(0);
+  is(shEntry.docshellID.toString(), historyID.toString());
 
   let tab2 = gBrowser.duplicateTab(tab);
   await BrowserTestUtils.browserLoaded(tab2.linkedBrowser);
 
-  if (!Services.appinfo.sessionHistoryInParent) {
-    await SpecialPowers.spawn(tab2.linkedBrowser, [], function () {
-      let docshell = content.window.docShell.QueryInterface(
-        Ci.nsIWebNavigation
-      );
-      let shEntry = docshell.sessionHistory.legacySHistory.getEntryAtIndex(0);
-      is(shEntry.docshellID.toString(), docshell.historyID.toString());
-    });
-  } else {
-    let historyID = tab2.linkedBrowser.browsingContext.historyID;
-    let shEntry =
-      tab2.linkedBrowser.browsingContext.sessionHistory.getEntryAtIndex(0);
-    is(shEntry.docshellID.toString(), historyID.toString());
-  }
+  historyID = tab2.linkedBrowser.browsingContext.historyID;
+  shEntry =
+    tab2.linkedBrowser.browsingContext.sessionHistory.getEntryAtIndex(0);
+  is(shEntry.docshellID.toString(), historyID.toString());
 
   BrowserTestUtils.removeTab(tab);
   BrowserTestUtils.removeTab(tab2);
@@ -47,24 +27,10 @@ add_task(async function contentToChromeNavigate() {
   let tab = BrowserTestUtils.addTab(gBrowser, TEST_URL);
   await BrowserTestUtils.browserLoaded(tab.linkedBrowser);
 
-  if (!Services.appinfo.sessionHistoryInParent) {
-    await SpecialPowers.spawn(tab.linkedBrowser, [], function () {
-      let docshell = content.window.docShell.QueryInterface(
-        Ci.nsIWebNavigation
-      );
-      let sh = docshell.sessionHistory;
-      is(sh.count, 1);
-      is(
-        sh.legacySHistory.getEntryAtIndex(0).docshellID.toString(),
-        docshell.historyID.toString()
-      );
-    });
-  } else {
-    let historyID = tab.linkedBrowser.browsingContext.historyID;
-    let sh = tab.linkedBrowser.browsingContext.sessionHistory;
-    is(sh.count, 1);
-    is(sh.getEntryAtIndex(0).docshellID.toString(), historyID.toString());
-  }
+  let historyID = tab.linkedBrowser.browsingContext.historyID;
+  let sh = tab.linkedBrowser.browsingContext.sessionHistory;
+  is(sh.count, 1);
+  is(sh.getEntryAtIndex(0).docshellID.toString(), historyID.toString());
 
   // Force the browser to navigate to the chrome process.
   BrowserTestUtils.loadURIString(tab.linkedBrowser, "about:config");
@@ -74,31 +40,17 @@ add_task(async function contentToChromeNavigate() {
   let docShell = tab.linkedBrowser.frameLoader.docShell;
 
   // 'cause we're in the chrome process, we can just directly poke at the shistory.
-  if (!Services.appinfo.sessionHistoryInParent) {
-    let sh = docShell.QueryInterface(Ci.nsIWebNavigation).sessionHistory;
-
-    is(sh.count, 2);
-    is(
-      sh.legacySHistory.getEntryAtIndex(0).docshellID.toString(),
-      docShell.historyID.toString()
-    );
-    is(
-      sh.legacySHistory.getEntryAtIndex(1).docshellID.toString(),
-      docShell.historyID.toString()
-    );
-  } else {
-    let sh = docShell.browsingContext.sessionHistory;
-
-    is(sh.count, 2);
-    is(
-      sh.getEntryAtIndex(0).docshellID.toString(),
-      docShell.historyID.toString()
-    );
-    is(
-      sh.getEntryAtIndex(1).docshellID.toString(),
-      docShell.historyID.toString()
-    );
-  }
+  sh = docShell.browsingContext.sessionHistory;
+
+  is(sh.count, 2);
+  is(
+    sh.getEntryAtIndex(0).docshellID.toString(),
+    docShell.historyID.toString()
+  );
+  is(
+    sh.getEntryAtIndex(1).docshellID.toString(),
+    docShell.historyID.toString()
+  );
 
   BrowserTestUtils.removeTab(tab);
 });
diff --git a/browser/components/sessionstore/test/browser_history_persist.js b/browser/components/sessionstore/test/browser_history_persist.js
index b45a2b6779..4b098a9edb 100644
--- a/browser/components/sessionstore/test/browser_history_persist.js
+++ b/browser/components/sessionstore/test/browser_history_persist.js
@@ -25,54 +25,27 @@ add_task(async function check_history_not_persisted() {
   browser = tab.linkedBrowser;
   await promiseTabState(tab, state);
 
-  if (!SpecialPowers.Services.appinfo.sessionHistoryInParent) {
-    await SpecialPowers.spawn(browser, [], function () {
-      let sessionHistory =
-        docShell.browsingContext.childSessionHistory.legacySHistory;
-
-      is(sessionHistory.count, 1, "Should be a single history entry");
-      is(
-        sessionHistory.getEntryAtIndex(0).URI.spec,
-        "about:blank",
-        "Should be the right URL"
-      );
-    });
-  } else {
-    let sessionHistory = browser.browsingContext.sessionHistory;
-
-    is(sessionHistory.count, 1, "Should be a single history entry");
-    is(
-      sessionHistory.getEntryAtIndex(0).URI.spec,
-      "about:blank",
-      "Should be the right URL"
-    );
-  }
+  let sessionHistory = browser.browsingContext.sessionHistory;
+
+  is(sessionHistory.count, 1, "Should be a single history entry");
+  is(
+    sessionHistory.getEntryAtIndex(0).URI.spec,
+    "about:blank",
+    "Should be the right URL"
+  );
 
   // Load a new URL into the tab, it should replace the about:blank history entry
   BrowserTestUtils.loadURIString(browser, "about:robots");
   await promiseBrowserLoaded(browser, false, "about:robots");
-  if (!SpecialPowers.Services.appinfo.sessionHistoryInParent) {
-    await SpecialPowers.spawn(browser, [], function () {
-      let sessionHistory =
-        docShell.browsingContext.childSessionHistory.legacySHistory;
-
-      is(sessionHistory.count, 1, "Should be a single history entry");
-      is(
-        sessionHistory.getEntryAtIndex(0).URI.spec,
-        "about:robots",
-        "Should be the right URL"
-      );
-    });
-  } else {
-    let sessionHistory = browser.browsingContext.sessionHistory;
-
-    is(sessionHistory.count, 1, "Should be a single history entry");
-    is(
-      sessionHistory.getEntryAtIndex(0).URI.spec,
-      "about:robots",
-      "Should be the right URL"
-    );
-  }
+
+  sessionHistory = browser.browsingContext.sessionHistory;
+
+  is(sessionHistory.count, 1, "Should be a single history entry");
+  is(
+    sessionHistory.getEntryAtIndex(0).URI.spec,
+    "about:robots",
+    "Should be the right URL"
+  );
 
   // Cleanup.
   BrowserTestUtils.removeTab(tab);
@@ -99,64 +72,33 @@ add_task(async function check_history_default_persisted() {
   tab = BrowserTestUtils.addTab(gBrowser, "about:blank");
   browser = tab.linkedBrowser;
   await promiseTabState(tab, state);
-  if (!SpecialPowers.Services.appinfo.sessionHistoryInParent) {
-    await SpecialPowers.spawn(browser, [], function () {
-      let sessionHistory =
-        docShell.browsingContext.childSessionHistory.legacySHistory;
-
-      is(sessionHistory.count, 1, "Should be a single history entry");
-      is(
-        sessionHistory.getEntryAtIndex(0).URI.spec,
-        "about:blank",
-        "Should be the right URL"
-      );
-    });
-  } else {
-    let sessionHistory = browser.browsingContext.sessionHistory;
-
-    is(sessionHistory.count, 1, "Should be a single history entry");
-    is(
-      sessionHistory.getEntryAtIndex(0).URI.spec,
-      "about:blank",
-      "Should be the right URL"
-    );
-  }
+
+  let sessionHistory = browser.browsingContext.sessionHistory;
+
+  is(sessionHistory.count, 1, "Should be a single history entry");
+  is(
+    sessionHistory.getEntryAtIndex(0).URI.spec,
+    "about:blank",
+    "Should be the right URL"
+  );
 
   // Load a new URL into the tab, it should replace the about:blank history entry
   BrowserTestUtils.loadURIString(browser, "about:robots");
   await promiseBrowserLoaded(browser, false, "about:robots");
-  if (!SpecialPowers.Services.appinfo.sessionHistoryInParent) {
-    await SpecialPowers.spawn(browser, [], function () {
-      let sessionHistory =
-        docShell.browsingContext.childSessionHistory.legacySHistory;
-
-      is(sessionHistory.count, 2, "Should be two history entries");
-      is(
-        sessionHistory.getEntryAtIndex(0).URI.spec,
-        "about:blank",
-        "Should be the right URL"
-      );
-      is(
-        sessionHistory.getEntryAtIndex(1).URI.spec,
-        "about:robots",
-        "Should be the right URL"
-      );
-    });
-  } else {
-    let sessionHistory = browser.browsingContext.sessionHistory;
-
-    is(sessionHistory.count, 2, "Should be two history entries");
-    is(
-      sessionHistory.getEntryAtIndex(0).URI.spec,
-      "about:blank",
-      "Should be the right URL"
-    );
-    is(
-      sessionHistory.getEntryAtIndex(1).URI.spec,
-      "about:robots",
-      "Should be the right URL"
-    );
-  }
+
+  sessionHistory = browser.browsingContext.sessionHistory;
+
+  is(sessionHistory.count, 2, "Should be two history entries");
+  is(
+    sessionHistory.getEntryAtIndex(0).URI.spec,
+    "about:blank",
+    "Should be the right URL"
+  );
+  is(
+    sessionHistory.getEntryAtIndex(1).URI.spec,
+    "about:robots",
+    "Should be the right URL"
+  );
 
   // Cleanup.
   BrowserTestUtils.removeTab(tab);
diff --git a/browser/components/sessionstore/test/browser_send_async_message_oom.js b/browser/components/sessionstore/test/browser_send_async_message_oom.js
deleted file mode 100644
index 7e807f2fbd..0000000000
--- a/browser/components/sessionstore/test/browser_send_async_message_oom.js
+++ /dev/null
@@ -1,75 +0,0 @@
-/* Any copyright is dedicated to the Public Domain.
-   http://creativecommons.org/publicdomain/zero/1.0/ */
-/* eslint-disable mozilla/no-arbitrary-setTimeout */
-
-const HISTOGRAM_NAME = "FX_SESSION_RESTORE_SEND_UPDATE_CAUSED_OOM";
-
-/**
- * Test that an OOM in sendAsyncMessage in a framescript will be reported
- * to Telemetry.
- */
-
-add_setup(async function () {
-  Services.telemetry.canRecordExtended = true;
-});
-
-function frameScript() {
-  // Make send[A]syncMessage("SessionStore:update", ...) simulate OOM.
-  // Other operations are unaffected.
-  let mm = docShell.messageManager;
-
-  let wrap = function (original) {
-    return function (name, ...args) {
-      if (name != "SessionStore:update") {
-        return original(name, ...args);
-      }
-      throw new Components.Exception(
-        "Simulated OOM",
-        Cr.NS_ERROR_OUT_OF_MEMORY
-      );
-    };
-  };
-
-  mm.sendAsyncMessage = wrap(mm.sendAsyncMessage.bind(mm));
-  mm.sendSyncMessage = wrap(mm.sendSyncMessage.bind(mm));
-}
-
-add_task(async function () {
-  // Capture original state.
-  let snapshot = Services.telemetry.getHistogramById(HISTOGRAM_NAME).snapshot();
-
-  // Open a browser, configure it to cause OOM.
-  let newTab = BrowserTestUtils.addTab(gBrowser, "about:robots");
-  let browser = newTab.linkedBrowser;
-  await ContentTask.spawn(browser, null, frameScript);
-
-  let promiseReported = new Promise(resolve => {
-    browser.messageManager.addMessageListener("SessionStore:error", resolve);
-  });
-
-  // Attempt to flush. This should fail.
-  let promiseFlushed = TabStateFlusher.flush(browser);
-  promiseFlushed.then(success => {
-    if (success) {
-      throw new Error("Flush should have failed");
-    }
-  });
-
-  // The frame script should report an error.
-  await promiseReported;
-
-  // Give us some time to handle that error.
-  await new Promise(resolve => setTimeout(resolve, 10));
-
-  // By now, Telemetry should have been updated.
-  let snapshot2 = Services.telemetry
-    .getHistogramById(HISTOGRAM_NAME)
-    .snapshot();
-  gBrowser.removeTab(newTab);
-
-  Assert.ok(snapshot2.sum > snapshot.sum);
-});
-
-add_task(async function cleanup() {
-  Services.telemetry.canRecordExtended = false;
-});
diff --git a/browser/components/sessionstore/test/browser_sessionHistory.js b/browser/components/sessionstore/test/browser_sessionHistory.js
index ebdf0055e9..a3eb4abd42 100644
--- a/browser/components/sessionstore/test/browser_sessionHistory.js
+++ b/browser/components/sessionstore/test/browser_sessionHistory.js
@@ -296,12 +296,9 @@ add_task(async function test_slow_subframe_load() {
  * Ensure that document wireframes can be persisted when they're enabled.
  */
 add_task(async function test_wireframes() {
-  // Wireframes only works when Fission and SHIP are enabled.
-  if (
-    !Services.appinfo.fissionAutostart ||
-    !Services.appinfo.sessionHistoryInParent
-  ) {
-    ok(true, "Skipping test_wireframes when Fission or SHIP is not enabled.");
+  // Wireframes only works when Fission is enabled.
+  if (!Services.appinfo.fissionAutostart) {
+    ok(true, "Skipping test_wireframes when Fission is not enabled.");
     return;
   }
 
diff --git a/browser/components/sessionstore/test/head.js b/browser/components/sessionstore/test/head.js
index d73c098eea..a43a6ac0a2 100644
--- a/browser/components/sessionstore/test/head.js
+++ b/browser/components/sessionstore/test/head.js
@@ -671,35 +671,9 @@ function setPropertyOfFormField(browserContext, selector, propName, newValue) {
 }
 
 function promiseOnHistoryReplaceEntry(browser) {
-  if (SpecialPowers.Services.appinfo.sessionHistoryInParent) {
-    return new Promise(resolve => {
-      let sessionHistory = browser.browsingContext?.sessionHistory;
-      if (sessionHistory) {
-        var historyListener = {
-          OnHistoryNewEntry() {},
-          OnHistoryGotoIndex() {},
-          OnHistoryPurge() {},
-          OnHistoryReload() {
-            return true;
-          },
-
-          OnHistoryReplaceEntry() {
-            resolve();
-          },
-
-          QueryInterface: ChromeUtils.generateQI([
-            "nsISHistoryListener",
-            "nsISupportsWeakReference",
-          ]),
-        };
-
-        sessionHistory.addSHistoryListener(historyListener);
-      }
-    });
-  }
-
-  return SpecialPowers.spawn(browser, [], () => {
-    return new Promise(resolve => {
+  return new Promise(resolve => {
+    let sessionHistory = browser.browsingContext?.sessionHistory;
+    if (sessionHistory) {
       var historyListener = {
         OnHistoryNewEntry() {},
         OnHistoryGotoIndex() {},
@@ -718,13 +692,8 @@ function promiseOnHistoryReplaceEntry(browser) {
         ]),
       };
 
-      var { sessionHistory } = this.docShell.QueryInterface(
-        Ci.nsIWebNavigation
-      );
-      if (sessionHistory) {
-        sessionHistory.legacySHistory.addSHistoryListener(historyListener);
-      }
-    });
+      sessionHistory.addSHistoryListener(historyListener);
+    }
   });
 }