GuestView: Move lifetime management out of content

chrome/renderer/resources/extensions/app_view.js

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 var DocumentNatives = requireNative('document_natives');
 var GuestViewInternal =
     require('binding').Binding.create('guestViewInternal').generate();
 var IdGenerator = requireNative('id_generator');
 var guestViewInternalNatives = requireNative('guest_view_internal');
 
@@ skipping 52 matching lines @@
       this.attachWindow(guestInstanceId);
       if (callback) {
         callback(true);
       }
     }.bind(this)
   );
 };
 
 AppViewInternal.prototype.attachWindow = function(guestInstanceId) {
   this.guestInstanceId = guestInstanceId;
+  if (!this.internalInstanceId) {
+    return;
+  }
   var params = {
-    'instanceId': this.viewInstanceId,
+    'instanceId': this.viewInstanceId
   };
   this.browserPluginNode.style.visibility = 'visible';
   return guestViewInternalNatives.AttachGuest(
-      parseInt(this.browserPluginNode.getAttribute('internalinstanceid')),
+      this.internalInstanceId,
       guestInstanceId,
       params);
 };
 
+AppViewInternal.prototype.handleBrowserPluginAttributeMutation =
+    function(name, oldValue, newValue) {
+  if (name == 'internalinstanceid' && !oldValue && !!newValue) {
+    this.browserPluginNode.removeAttribute('internalinstanceid');
+    this.internalInstanceId = parseInt(newValue);
+
+    if (!!this.guestInstanceId && this.guestInstanceId != 0) {
+      var params = {
+        'instanceId': this.viewInstanceId
+      };
+      guestViewInternalNatives.AttachGuest(
+          this.internalInstanceId,
+          this.guestInstanceId,
+          params);
+    }
+    return;
+  }
+};
+
+AppViewInternal.prototype.reset = function() {
+  if (this.guestInstanceId) {
+    GuestViewInternal.destroyGuest(this.guestInstanceId);
+    this.guestInstanceId = undefined;
+  }
+};
+
 function registerBrowserPluginElement() {
   var proto = Object.create(HTMLObjectElement.prototype);
 
   proto.createdCallback = function() {
     this.setAttribute('type', 'application/browser-plugin');
     this.style.width = '100%';
     this.style.height = '100%';
   };
 
   proto.attachedCallback = function() {
     // Load the plugin immediately.
     var unused = this.nonExistentAttribute;
   };
 
+  proto.attributeChangedCallback = function(name, oldValue, newValue) {
+    var internal = privates(this).internal;
+    if (!internal) {
+      return;
+    }
+    internal.handleBrowserPluginAttributeMutation(name, oldValue, newValue);
+  };
+
   AppViewInternal.BrowserPlugin =
       DocumentNatives.RegisterElement('appplugin', {extends: 'object',
                                                     prototype: proto});
 
   delete proto.createdCallback;
   delete proto.attachedCallback;
   delete proto.detachedCallback;
   delete proto.attributeChangedCallback;
 }
 
 function registerAppViewElement() {
   var proto = Object.create(HTMLElement.prototype);
 
   proto.createdCallback = function() {
     new AppViewInternal(this);
   };
 
+  proto.detachedCallback = function() {
+    var internal = privates(this).internal;
+    if (!internal) {
+      return;
+    }
+    internal.reset();
+  };
+
   proto.connect = function() {
     var internal = privates(this).internal;
     $Function.apply(internal.connect, internal, arguments);
   }
+
   window.AppView =
       DocumentNatives.RegisterElement('appview', {prototype: proto});
 
   // Delete the callbacks so developers cannot call them and produce unexpected
   // behavior.
   delete proto.createdCallback;
   delete proto.attachedCallback;
   delete proto.detachedCallback;
   delete proto.attributeChangedCallback;
 }
 
 var useCapture = true;
 window.addEventListener('readystatechange', function listener(event) {
   if (document.readyState == 'loading')
     return;
 
   registerBrowserPluginElement();
   registerAppViewElement();
   window.removeEventListener(event.type, listener, useCapture);
 }, useCapture);