GuestView: Move lifetime management out of content

chrome/renderer/resources/extensions/extension_options.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 ExtensionOptionsEvents =
     require('extensionOptionsEvents').ExtensionOptionsEvents;
 var GuestViewInternal =
     require('binding').Binding.create('guestViewInternal').generate();
 var IdGenerator = requireNative('id_generator');
 var utils = require('utils');
 var guestViewInternalNatives = requireNative('guest_view_internal');
 
 // Mapping of the autosize attribute names to default values
 var AUTO_SIZE_ATTRIBUTES = {
   'autosize': 'on',
   'maxheight': window.innerHeight,
   'maxwidth': window.innerWidth,
   'minheight': 32,
   'minwidth': 32
 };
 
 function ExtensionOptionsInternal(extensionoptionsNode) {
   privates(extensionoptionsNode).internal = this;
   this.extensionoptionsNode = extensionoptionsNode;
   this.viewInstanceId = IdGenerator.GetNextId();
+  this.guestInstanceId = 0;
+  this.elementAttached = false;
+  this.pendingGuestCreation = false;
 
   this.autosizeDeferred = false;
 
   // on* Event handlers.
   this.eventHandlers = {};
 
   // setupEventProperty is normally called in extension_options_events.js to
   // register events, but the createfailed event is registered here because
   // the event is fired from here instead of through
   // extension_options_events.js.
@@ skipping 24 matching lines @@
         'minwidth': parseInt(this.minwidth || 0)
       });
 };
 
 ExtensionOptionsInternal.prototype.createBrowserPluginNode = function() {
   var browserPluginNode = new ExtensionOptionsInternal.BrowserPlugin();
   privates(browserPluginNode).internal = this;
   return browserPluginNode;
 };
 
-ExtensionOptionsInternal.prototype.createGuest = function() {
+ExtensionOptionsInternal.prototype.createGuestIfNecessary = function() {
+  if (!this.elementAttached || this.pendingGuestCreation) {
+    return;
+  }
+  if (this.guestInstanceId != 0) {
+    this.attachWindow();
+    return;
+  }
   var params = {
     'extensionId': this.extensionId,
   };
   GuestViewInternal.createGuest(
       'extensionoptions',
       params,
       function(guestInstanceId) {
+        this.pendingGuestCreation = false;
+        if (guestInstanceId && !this.elementAttached) {
+          GuestViewInternal.destroyGuest(guestInstanceId);
+          guestInstanceId = 0;
+        }
         if (guestInstanceId == 0) {
           // Fire a createfailed event here rather than in ExtensionOptionsGuest
           // because the guest will not be created, and cannot fire an event.
           this.initCalled = false;
           var createFailedEvent = new Event('createfailed', { bubbles: true });
           this.dispatchEvent(createFailedEvent);
         } else {
           this.guestInstanceId = guestInstanceId;
           this.attachWindow();
         }
-      }.bind(this));
+      }.bind(this)
+  );
+  this.pendingGuestCreation = true;
 };
 
 ExtensionOptionsInternal.prototype.dispatchEvent =
     function(extensionOptionsEvent) {
   return this.extensionoptionsNode.dispatchEvent(extensionOptionsEvent);
 };
 
 ExtensionOptionsInternal.prototype.handleExtensionOptionsAttributeMutation =
     function(name, oldValue, newValue) {
   // We treat null attribute (attribute removed) and the empty string as
   // one case.
   oldValue = oldValue || '';
   newValue = newValue || '';
 
   if (oldValue === newValue)
     return;
 
   if (name == 'extension' && !oldValue && newValue) {
     this.extensionId = newValue;
     // If the browser plugin is not ready then don't create the guest until
     // it is ready (in handleBrowserPluginAttributeMutation).
     if (!this.internalInstanceId)
       return;
 
     // If a guest view does not exist then create one.
     if (!this.guestInstanceId) {
-      this.createGuest();
+      this.createGuestIfNecessary();
       return;
     }
     // TODO(ericzeng): Implement navigation to another guest view if we want
     // that functionality.
   } else if (AUTO_SIZE_ATTRIBUTES.hasOwnProperty(name) > -1) {
     this[name] = newValue;
     this.resetSizeConstraintsIfInvalid();
 
     if (!this.guestInstanceId)
       return;
 
     GuestViewInternal.setAutoSize(this.guestInstanceId, {
       'enableAutoSize': this.extensionoptionsNode.hasAttribute('autosize'),
       'min': {
         'width': parseInt(this.minwidth || 0),
         'height': parseInt(this.minheight || 0)
       },
       'max': {
         'width': parseInt(this.maxwidth || 0),
         'height': parseInt(this.maxheight || 0)
       }
     });
   }
 };
 
 ExtensionOptionsInternal.prototype.handleBrowserPluginAttributeMutation =
     function(name, oldValue, newValue) {
   if (name == 'internalinstanceid' && !oldValue && !!newValue) {
+    this.elementAttached = true;
     this.internalInstanceId = parseInt(newValue);
     this.browserPluginNode.removeAttribute('internalinstanceid');
     if (this.extensionId)
-      this.createGuest();
+      this.createGuestIfNecessary();
 
   }
 };
 
 ExtensionOptionsInternal.prototype.onSizeChanged =
     function(newWidth, newHeight, oldWidth, oldHeight) {
   if (this.autosizeDeferred) {
     this.deferredAutoSizeState = {
       newWidth: newWidth,
       newHeight: newHeight,
@@ skipping 127 matching lines @@
  */
 ExtensionOptionsInternal.prototype.resumeDeferredAutoSize = function() {
   if (this.autosizeDeferred) {
     this.resize(this.deferredAutoSizeState.newWidth,
                 this.deferredAutoSizeState.newHeight,
                 this.deferredAutoSizeState.oldWidth,
                 this.deferredAutoSizeState.oldHeight);
   }
 };
 
+ExtensionOptionsInternal.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.attributeChangedCallback = function(name, oldValue, newValue) {
@@ skipping 18 matching lines @@
   delete proto.attributeChangedCallback;
 }
 
 function registerExtensionOptionsElement() {
   var proto = Object.create(HTMLElement.prototype);
 
   proto.createdCallback = function() {
     new ExtensionOptionsInternal(this);
   };
 
+  proto.detachedCallback = function() {
+    var internal = privates(this).internal;
+    if (!internal) {
+      return;
+    }
+    internal.elementAttached = false;
+    internal.reset();
+  };
+
   proto.attributeChangedCallback = function(name, oldValue, newValue) {
     var internal = privates(this).internal;
-    if (!internal)
+    if (!internal) {
       return;
+    }
     internal.handleExtensionOptionsAttributeMutation(name, oldValue, newValue);
   };
 
   var methods = [
     'setDeferAutoSize',
     'resumeDeferredAutoSize'
   ];
 
   // Forward proto.foo* method calls to ExtensionOptionsInternal.foo*.
   for (var i = 0; methods[i]; ++i) {
@@ skipping 19 matching lines @@
 
 var useCapture = true;
 window.addEventListener('readystatechange', function listener(event) {
   if (document.readyState == 'loading')
     return;
 
   registerBrowserPluginElement();
   registerExtensionOptionsElement();
   window.removeEventListener(event.type, listener, useCapture);
 }, useCapture);