GuestView: Move lifetime management out of content

chrome/renderer/resources/extensions/app_view.js

Index: chrome/renderer/resources/extensions/app_view.js
diff --git a/chrome/renderer/resources/extensions/app_view.js b/chrome/renderer/resources/extensions/app_view.js
index 968340b1f46a79271c6d924ffbe0680394507d3a..2cadb5933d62bbfe1bdfc2f6c4e30039d8c9681c 100644
--- a/chrome/renderer/resources/extensions/app_view.js
+++ b/chrome/renderer/resources/extensions/app_view.js
@@ -70,16 +70,45 @@ AppViewInternal.prototype.connect = function(app, data, callback) {
 
 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);
 
@@ -94,6 +123,14 @@ function registerBrowserPluginElement() {
     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});
@@ -111,10 +148,19 @@ function registerAppViewElement() {
     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});