Bug 1648149 - Split GeckoViewContent in enable and init phases. r=snorp

This commit splits the `GeckoViewContent` actor in two parts:

- `GeckoViewContent` proper, which runs unconditionally and handles code that
  needs to run regardless of whether we have a delegate installed or not.

- `ContentDelegate` which runs only when a delegate is first installed.

This emulates the previous paradigm of installing some listeners only when the
delegate is installed.

I discussed it briefly with :nika and she thinks that splitting modules in two
should not affect performance in a measurable manner.

Note that actors cannot be registered per-window, so we will get messages from
all windows as long as one content delegate is registered.

Differential Revision: https://phabricator.services.mozilla.com/D86776

mobile/android/actors/ContentDelegateChild.jsm

@@ -0,0 +1,169 @@
+/* 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 { GeckoViewActorChild } = ChromeUtils.import(
+  "resource://gre/modules/GeckoViewActorChild.jsm"
+);
+
+var { XPCOMUtils } = ChromeUtils.import(
+  "resource://gre/modules/XPCOMUtils.jsm"
+);
+
+var { Services } = ChromeUtils.import("resource://gre/modules/Services.jsm");
+
+XPCOMUtils.defineLazyModuleGetters(this, {
+  ManifestObtainer: "resource://gre/modules/ManifestObtainer.jsm",
+});
+
+var EXPORTED_SYMBOLS = ["ContentDelegateChild"];
+
+class ContentDelegateChild extends GeckoViewActorChild {
+  notifyParentOfViewportFit() {
+    if (this.triggerViewportFitChange) {
+      this.contentWindow.cancelIdleCallback(this.triggerViewportFitChange);
+    }
+    this.triggerViewportFitChange = this.contentWindow.requestIdleCallback(
+      () => {
+        this.triggerViewportFitChange = null;
+        const viewportFit = this.contentWindow.windowUtils.getViewportFitInfo();
+        if (this.lastViewportFit === viewportFit) {
+          return;
+        }
+        this.lastViewportFit = viewportFit;
+        this.eventDispatcher.sendRequest({
+          type: "GeckoView:DOMMetaViewportFit",
+          viewportfit: viewportFit,
+        });
+      }
+    );
+  }
+
+  // eslint-disable-next-line complexity
+  handleEvent(aEvent) {
+    debug`handleEvent: ${aEvent.type}`;
+
+    switch (aEvent.type) {
+      case "contextmenu": {
+        function nearestParentAttribute(aNode, aAttribute) {
+          while (
+            aNode &&
+            aNode.hasAttribute &&
+            !aNode.hasAttribute(aAttribute)
+          ) {
+            aNode = aNode.parentNode;
+          }
+          return aNode && aNode.getAttribute && aNode.getAttribute(aAttribute);
+        }
+
+        function createAbsoluteUri(aBaseUri, aUri) {
+          if (!aUri || !aBaseUri || !aBaseUri.displaySpec) {
+            return null;
+          }
+          return Services.io.newURI(aUri, null, aBaseUri).displaySpec;
+        }
+
+        const node = aEvent.composedTarget;
+        const baseUri = node.ownerDocument.baseURIObject;
+        const uri = createAbsoluteUri(
+          baseUri,
+          nearestParentAttribute(node, "href")
+        );
+        const title = nearestParentAttribute(node, "title");
+        const alt = nearestParentAttribute(node, "alt");
+        const elementType = ChromeUtils.getClassName(node);
+        const isImage = elementType === "HTMLImageElement";
+        const isMedia =
+          elementType === "HTMLVideoElement" ||
+          elementType === "HTMLAudioElement";
+        const elementSrc =
+          (isImage || isMedia) && (node.currentSrc || node.src);
+
+        if (uri || isImage || isMedia) {
+          const msg = {
+            type: "GeckoView:ContextMenu",
+            screenX: aEvent.screenX,
+            screenY: aEvent.screenY,
+            baseUri: (baseUri && baseUri.displaySpec) || null,
+            uri,
+            title,
+            alt,
+            elementType,
+            elementSrc: elementSrc || null,
+          };
+
+          this.eventDispatcher.sendRequest(msg);
+          aEvent.preventDefault();
+        }
+        break;
+      }
+      case "MozDOMFullscreen:Request": {
+        this.sendAsyncMessage("GeckoView:DOMFullscreenRequest", {});
+        break;
+      }
+      case "MozDOMFullscreen:Entered":
+      case "MozDOMFullscreen:Exited":
+        // Content may change fullscreen state by itself, and we should ensure
+        // that the parent always exits fullscreen when content has left
+        // full screen mode.
+        if (this.contentWindow?.document.fullscreenElement) {
+          break;
+        }
+      // fall-through
+      case "MozDOMFullscreen:Exit":
+        this.sendAsyncMessage("GeckoView:DOMFullscreenExit", {});
+        break;
+      case "DOMMetaViewportFitChanged":
+        if (aEvent.originalTarget.ownerGlobal == this.contentWindow) {
+          this.notifyParentOfViewportFit();
+        }
+        break;
+      case "DOMTitleChanged":
+        this.eventDispatcher.sendRequest({
+          type: "GeckoView:DOMTitleChanged",
+          title: this.contentWindow.document.title,
+        });
+        break;
+      case "DOMWindowClose":
+        if (!aEvent.isTrusted) {
+          return;
+        }
+
+        aEvent.preventDefault();
+        this.eventDispatcher.sendRequest({
+          type: "GeckoView:DOMWindowClose",
+        });
+        break;
+      case "DOMContentLoaded": {
+        if (aEvent.originalTarget.ownerGlobal == this.contentWindow) {
+          // If loaded content doesn't have viewport-fit, parent still
+          // uses old value of previous content.
+          this.notifyParentOfViewportFit();
+        }
+        this.contentWindow.requestIdleCallback(async () => {
+          const manifest = await ManifestObtainer.contentObtainManifest(
+            this.contentWindow
+          );
+          if (manifest) {
+            this.eventDispatcher.sendRequest({
+              type: "GeckoView:WebAppManifest",
+              manifest,
+            });
+          }
+        });
+        break;
+      }
+      case "MozFirstContentfulPaint": {
+        this.eventDispatcher.sendRequest({
+          type: "GeckoView:FirstContentfulPaint",
+        });
+        break;
+      }
+    }
+  }
+}
+
+// eslint-disable-next-line no-unused-vars
+const { debug, warn } = ContentDelegateChild.initLogging(
+  "ContentDelegateChild"
+);

mobile/android/actors/ContentDelegateParent.jsm

@@ -3,15 +3,15 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 "use strict";
 
-var EXPORTED_SYMBOLS = ["GeckoViewContentParent"];
+var EXPORTED_SYMBOLS = ["ContentDelegateParent"];
 
 const { GeckoViewUtils } = ChromeUtils.import(
   "resource://gre/modules/GeckoViewUtils.jsm"
 );
 
-const { debug, warn } = GeckoViewUtils.initLogging("GeckoViewContentParent"); // eslint-disable-line no-unused-vars
+const { debug, warn } = GeckoViewUtils.initLogging("ContentDelegateParent"); // eslint-disable-line no-unused-vars
 
-class GeckoViewContentParent extends JSWindowActorParent {
+class ContentDelegateParent extends JSWindowActorParent {
   async receiveMessage(aMsg) {
     debug`receiveMessage: ${aMsg.name} ${aMsg}`;
 

mobile/android/actors/GeckoViewContentChild.jsm

@@ -25,7 +25,6 @@ const SCROLL_BEHAVIOR_AUTO = 1;
 
 XPCOMUtils.defineLazyModuleGetters(this, {
   E10SUtils: "resource://gre/modules/E10SUtils.jsm",
-  ManifestObtainer: "resource://gre/modules/ManifestObtainer.jsm",
   PrivacyFilter: "resource://gre/modules/sessionstore/PrivacyFilter.jsm",
   SessionHistory: "resource://gre/modules/sessionstore/SessionHistory.jsm",
   Utils: "resource://gre/modules/sessionstore/Utils.jsm",
@@ -65,26 +64,6 @@ class GeckoViewContentChild extends GeckoViewActorChild {
     return windowUtils.SCROLL_MODE_SMOOTH;
   }
 
-  notifyParentOfViewportFit() {
-    if (this.triggerViewportFitChange) {
-      this.contentWindow.cancelIdleCallback(this.triggerViewportFitChange);
-    }
-    this.triggerViewportFitChange = this.contentWindow.requestIdleCallback(
-      () => {
-        this.triggerViewportFitChange = null;
-        const viewportFit = this.contentWindow.windowUtils.getViewportFitInfo();
-        if (this.lastViewportFit === viewportFit) {
-          return;
-        }
-        this.lastViewportFit = viewportFit;
-        this.eventDispatcher.sendRequest({
-          type: "GeckoView:DOMMetaViewportFit",
-          viewportfit: viewportFit,
-        });
-      }
-    );
-  }
-
   collectSessionState() {
     const { docShell, contentWindow } = this;
     const history = SessionHistory.collect(docShell);
@@ -355,96 +334,6 @@ class GeckoViewContentChild extends GeckoViewActorChild {
     debug`handleEvent: ${aEvent.type}`;
 
     switch (aEvent.type) {
-      case "contextmenu": {
-        function nearestParentAttribute(aNode, aAttribute) {
-          while (
-            aNode &&
-            aNode.hasAttribute &&
-            !aNode.hasAttribute(aAttribute)
-          ) {
-            aNode = aNode.parentNode;
-          }
-          return aNode && aNode.getAttribute && aNode.getAttribute(aAttribute);
-        }
-
-        function createAbsoluteUri(aBaseUri, aUri) {
-          if (!aUri || !aBaseUri || !aBaseUri.displaySpec) {
-            return null;
-          }
-          return Services.io.newURI(aUri, null, aBaseUri).displaySpec;
-        }
-
-        const node = aEvent.composedTarget;
-        const baseUri = node.ownerDocument.baseURIObject;
-        const uri = createAbsoluteUri(
-          baseUri,
-          nearestParentAttribute(node, "href")
-        );
-        const title = nearestParentAttribute(node, "title");
-        const alt = nearestParentAttribute(node, "alt");
-        const elementType = ChromeUtils.getClassName(node);
-        const isImage = elementType === "HTMLImageElement";
-        const isMedia =
-          elementType === "HTMLVideoElement" ||
-          elementType === "HTMLAudioElement";
-        const elementSrc =
-          (isImage || isMedia) && (node.currentSrc || node.src);
-
-        if (uri || isImage || isMedia) {
-          const msg = {
-            type: "GeckoView:ContextMenu",
-            screenX: aEvent.screenX,
-            screenY: aEvent.screenY,
-            baseUri: (baseUri && baseUri.displaySpec) || null,
-            uri,
-            title,
-            alt,
-            elementType,
-            elementSrc: elementSrc || null,
-          };
-
-          this.eventDispatcher.sendRequest(msg);
-          aEvent.preventDefault();
-        }
-        break;
-      }
-      case "MozDOMFullscreen:Request": {
-        this.sendAsyncMessage("GeckoView:DOMFullscreenRequest", {});
-        break;
-      }
-      case "MozDOMFullscreen:Entered":
-      case "MozDOMFullscreen:Exited":
-        // Content may change fullscreen state by itself, and we should ensure
-        // that the parent always exits fullscreen when content has left
-        // full screen mode.
-        if (this.contentWindow?.document.fullscreenElement) {
-          break;
-        }
-      // fall-through
-      case "MozDOMFullscreen:Exit":
-        this.sendAsyncMessage("GeckoView:DOMFullscreenExit", {});
-        break;
-      case "DOMMetaViewportFitChanged":
-        if (aEvent.originalTarget.ownerGlobal == this.contentWindow) {
-          this.notifyParentOfViewportFit();
-        }
-        break;
-      case "DOMTitleChanged":
-        this.eventDispatcher.sendRequest({
-          type: "GeckoView:DOMTitleChanged",
-          title: this.contentWindow.document.title,
-        });
-        break;
-      case "DOMWindowClose":
-        if (!aEvent.isTrusted) {
-          return;
-        }
-
-        aEvent.preventDefault();
-        this.eventDispatcher.sendRequest({
-          type: "GeckoView:DOMWindowClose",
-        });
-        break;
       case "mozcaretstatechanged":
         if (
           aEvent.reason === "presscaret" ||
@@ -456,31 +345,6 @@ class GeckoViewContentChild extends GeckoViewActorChild {
           });
         }
         break;
-      case "DOMContentLoaded": {
-        if (aEvent.originalTarget.ownerGlobal == this.contentWindow) {
-          // If loaded content doesn't have viewport-fit, parent still
-          // uses old value of previous content.
-          this.notifyParentOfViewportFit();
-        }
-        this.contentWindow.requestIdleCallback(async () => {
-          const manifest = await ManifestObtainer.contentObtainManifest(
-            this.contentWindow
-          );
-          if (manifest) {
-            this.eventDispatcher.sendRequest({
-              type: "GeckoView:WebAppManifest",
-              manifest,
-            });
-          }
-        });
-        break;
-      }
-      case "MozFirstContentfulPaint": {
-        this.eventDispatcher.sendRequest({
-          type: "GeckoView:FirstContentfulPaint",
-        });
-        break;
-      }
     }
   }
 }

mobile/android/actors/moz.build

@@ -7,8 +7,9 @@ with Files('**'):
 
 FINAL_TARGET_FILES.actors += [
     'BrowserTabParent.jsm',
+    'ContentDelegateChild.jsm',
+    'ContentDelegateParent.jsm',
     'GeckoViewContentChild.jsm',
-    'GeckoViewContentParent.jsm',
     'LoadURIDelegateChild.jsm',
     'WebBrowserChromeChild.jsm',
 ]

mobile/android/chrome/geckoview/geckoview.js

@@ -15,6 +15,7 @@ var { Services } = ChromeUtils.import("resource://gre/modules/Services.jsm");
 XPCOMUtils.defineLazyModuleGetters(this, {
   E10SUtils: "resource://gre/modules/E10SUtils.jsm",
   EventDispatcher: "resource://gre/modules/Messaging.jsm",
+  GeckoViewActorManager: "resource://gre/modules/GeckoViewActorManager.jsm",
   GeckoViewSettings: "resource://gre/modules/GeckoViewSettings.jsm",
   GeckoViewUtils: "resource://gre/modules/GeckoViewUtils.jsm",
   HistogramStopwatch: "resource://gre/modules/GeckoViewTelemetry.jsm",
@@ -346,6 +347,10 @@ class ModuleInfo {
     // onInitBrowser() override. However, load content module after initializing
     // browser, because we don't have a message manager before then.
     this._loadResource(onInit);
+    this._loadActors(onInit);
+    if (this._enabledOnInit) {
+      this._loadActors(onEnable);
+    }
 
     this._onInitPhase = onInit;
     this._onEnablePhase = onEnable;
@@ -383,6 +388,14 @@ class ModuleInfo {
     this._contentModuleLoaded = false;
   }
 
+  _loadActors(aPhase) {
+    if (!aPhase || !aPhase.actors) {
+      return;
+    }
+
+    GeckoViewActorManager.addJSWindowActors(aPhase.actors);
+  }
+
   /**
    * Load resource according to a phase object that contains possible keys,
    *
@@ -445,6 +458,7 @@ class ModuleInfo {
     if (aEnabled) {
       this._loadResource(this._onEnablePhase);
       this._loadFrameScript(this._onEnablePhase);
+      this._loadActors(this._onEnablePhase);
       if (this._impl) {
         this._impl.onEnable();
         this._impl.onSettingsUpdate();
@@ -518,6 +532,42 @@ function startup() {
       name: "GeckoViewContent",
       onInit: {
         resource: "resource://gre/modules/GeckoViewContent.jsm",
+        actors: {
+          GeckoViewContent: {
+            child: {
+              moduleURI: "resource:///actors/GeckoViewContentChild.jsm",
+              events: {
+                mozcaretstatechanged: { capture: true, mozSystemGroup: true },
+              },
+              allFrames: true,
+            },
+          },
+        },
+      },
+      onEnable: {
+        actors: {
+          ContentDelegate: {
+            parent: {
+              moduleURI: "resource:///actors/ContentDelegateParent.jsm",
+            },
+            child: {
+              moduleURI: "resource:///actors/ContentDelegateChild.jsm",
+              events: {
+                DOMContentLoaded: {},
+                DOMMetaViewportFitChanged: {},
+                DOMTitleChanged: {},
+                DOMWindowClose: {},
+                "MozDOMFullscreen:Entered": {},
+                "MozDOMFullscreen:Exit": {},
+                "MozDOMFullscreen:Exited": {},
+                "MozDOMFullscreen:Request": {},
+                MozFirstContentfulPaint: {},
+                contextmenu: { capture: true },
+              },
+              allFrames: true,
+            },
+          },
+        },
       },
     },
     {

mobile/android/components/geckoview/GeckoViewStartup.jsm

@@ -28,28 +28,6 @@ const JSWINDOWACTORS = {
       moduleURI: "resource:///actors/BrowserTabParent.jsm",
     },
   },
-  GeckoViewContent: {
-    parent: {
-      moduleURI: "resource:///actors/GeckoViewContentParent.jsm",
-    },
-    child: {
-      moduleURI: "resource:///actors/GeckoViewContentChild.jsm",
-      events: {
-        DOMContentLoaded: {},
-        DOMMetaViewportFitChanged: {},
-        DOMTitleChanged: {},
-        DOMWindowClose: {},
-        "MozDOMFullscreen:Entered": {},
-        "MozDOMFullscreen:Exit": {},
-        "MozDOMFullscreen:Exited": {},
-        "MozDOMFullscreen:Request": {},
-        MozFirstContentfulPaint: {},
-        contextmenu: { capture: true },
-        mozcaretstatechanged: { capture: true, mozSystemGroup: true },
-      },
-      allFrames: true,
-    },
-  },
   LoadURIDelegate: {
     child: {
       moduleURI: "resource:///actors/LoadURIDelegateChild.jsm",

mobile/android/modules/geckoview/GeckoViewActorManager.jsm

@@ -0,0 +1,33 @@
+/* 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";
+
+const EXPORTED_SYMBOLS = ["GeckoViewActorManager"];
+
+const { GeckoViewUtils } = ChromeUtils.import(
+  "resource://gre/modules/GeckoViewUtils.jsm"
+);
+
+const actors = new Set();
+
+var GeckoViewActorManager = {
+  addJSWindowActors(actors) {
+    for (const [actorName, actor] of Object.entries(actors)) {
+      this._register(actorName, actor);
+    }
+  },
+
+  _register(actorName, actor) {
+    if (actors.has(actorName)) {
+      // Actor already registered, nothing to do
+      return;
+    }
+
+    ChromeUtils.registerWindowActor(actorName, actor);
+    actors.add(actorName);
+  },
+};
+
+const { debug, warn } = GeckoViewUtils.initLogging("GeckoViewActorManager"); // eslint-disable-line no-unused-vars

mobile/android/modules/geckoview/moz.build

@@ -10,6 +10,7 @@ EXTRA_JS_MODULES += [
     'ContentCrashHandler.jsm',
     'DelayedInit.jsm',
     'GeckoViewActorChild.jsm',
+    'GeckoViewActorManager.jsm',
     'GeckoViewAutocomplete.jsm',
     'GeckoViewAutofill.jsm',
     'GeckoViewChildModule.jsm',