1 files changed, 60 insertions, 0 deletions
diff --git a/toolkit/actors/ThumbnailsChild.sys.mjs b/toolkit/actors/ThumbnailsChild.sys.mjs
new file mode 100644
index 0000000000..9ab6fc3b08
--- /dev/null
+++ b/toolkit/actors/ThumbnailsChild.sys.mjs
@@ -0,0 +1,60 @@
+/* vim: set ts=2 sw=2 sts=2 et tw=80: */
+/* 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/. */
+
+const lazy = {};
+
+ChromeUtils.defineESModuleGetters(lazy, {
+  PageThumbUtils: "resource://gre/modules/PageThumbUtils.sys.mjs",
+});
+
+export class ThumbnailsChild extends JSWindowActorChild {
+  receiveMessage(message) {
+    switch (message.name) {
+      case "Browser:Thumbnail:ContentInfo": {
+        let [width, height] = lazy.PageThumbUtils.getContentSize(
+          this.contentWindow
+        );
+        return { width, height };
+      }
+      case "Browser:Thumbnail:CheckState": {
+        /**
+         * Remote isSafeForCapture request handler for PageThumbs.
+         */
+        return new Promise(resolve =>
+          Services.tm.idleDispatchToMainThread(() => {
+            if (!this.manager) {
+              // If we have no manager, our actor has been destroyed, which
+              // means we can't respond, and trying to touch
+              // `this.contentWindow` or `this.browsingContext` will throw.
+              // The `sendQuery` call in the parent will already have been
+              // rejected when the actor was destroyed, so there's no need to
+              // reject our promise or log an additional error.
+              return;
+            }
+
+            let result = lazy.PageThumbUtils.shouldStoreContentThumbnail(
+              this.contentWindow,
+              this.browsingContext.docShell
+            );
+            resolve(result);
+          })
+        );
+      }
+      case "Browser:Thumbnail:GetOriginalURL": {
+        /**
+         * Remote GetOriginalURL request handler for PageThumbs.
+         */
+        let channel = this.browsingContext.docShell.currentDocumentChannel;
+        let channelError = lazy.PageThumbUtils.isChannelErrorResponse(channel);
+        let originalURL;
+        try {
+          originalURL = channel.originalURI.spec;
+        } catch (ex) {}
+        return { channelError, originalURL };
+      }
+    }
+    return undefined;
+  }
+}