1 files changed, 44 insertions, 0 deletions
diff --git a/remote/domains/content/Emulation.jsm b/remote/domains/content/Emulation.jsm
new file mode 100644
index 0000000000..323204202b
--- /dev/null
+++ b/remote/domains/content/Emulation.jsm
@@ -0,0 +1,44 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+var EXPORTED_SYMBOLS = ["Emulation"];
+
+const { ContentProcessDomain } = ChromeUtils.import(
+  "chrome://remote/content/domains/ContentProcessDomain.jsm"
+);
+
+class Emulation extends ContentProcessDomain {
+  // commands
+
+  /**
+   * Internal methods: the following methods are not part of CDP;
+   * note the _ prefix.
+   */
+
+  /**
+   * Waits until the viewport has reached the new dimensions.
+   */
+  async _awaitViewportDimensions({ width, height }) {
+    const win = this.content;
+
+    if (win.innerWidth === width && win.innerHeight === height) {
+      return;
+    }
+
+    await new Promise(resolve => {
+      win.addEventListener("resize", function resized() {
+        if (win.innerWidth === width && win.innerHeight === height) {
+          win.removeEventListener("resize", resized);
+          resolve();
+        }
+      });
+    });
+  }
+
+  _setDPPXOverride(dppx) {
+    this.docShell.contentViewer.overrideDPPX = dppx;
+  }
+}