Make <webview> use out-of-process iframe architecture.

extensions/renderer/resources/guest_view/guest_view_container.js

Index: extensions/renderer/resources/guest_view/guest_view_container.js
diff --git a/extensions/renderer/resources/guest_view/guest_view_container.js b/extensions/renderer/resources/guest_view/guest_view_container.js
index 5b6a736758ffe04dbec929baf704ec9289618e24..cb131a382121b1b961330742c094f926dfde203b 100644
--- a/extensions/renderer/resources/guest_view/guest_view_container.js
+++ b/extensions/renderer/resources/guest_view/guest_view_container.js
@@ -91,6 +91,10 @@ GuestViewContainer.prototype.createBrowserPluginElement = function() {
   return browserPluginElement;
 };
 
+GuestViewContainer.prototype.getBrowserPluginElement = function() {
+  return privates(this).browserPluginElement;
+};
+
 GuestViewContainer.prototype.setupFocusPropagation = function() {
   if (!this.element.hasAttribute('tabIndex')) {
     // GuestViewContainer needs a tabIndex in order to be focusable.
@@ -184,11 +188,17 @@ GuestViewContainer.prototype.setupAttributes = function() {};
 // Registers the browser plugin <object> custom element. |viewType| is the
 // name of the specific guestview container (e.g. 'webview').
 function registerBrowserPluginElement(viewType) {
-  var proto = Object.create(HTMLObjectElement.prototype);
+  //var proto = Object.create(HTMLObjectElement.prototype);
+  var proto = Object.create(HTMLIFrameElement.prototype);
+
+  var isSitePerProcess = GuestViewInternalNatives.IsSitePerProcess();
+  window.console.log('isSitePerProcess: ' + isSitePerProcess);
 
   proto.createdCallback = function() {
-    this.setAttribute('type', 'application/browser-plugin');
-    this.setAttribute('id', 'browser-plugin-' + IdGenerator.GetNextId());
+    if (!isSitePerProcess) {
+      this.setAttribute('type', 'application/browser-plugin');
+      this.setAttribute('id', 'browser-plugin-' + IdGenerator.GetNextId());
+    }
     this.style.width = '100%';
     this.style.height = '100%';
   };
@@ -198,17 +208,20 @@ function registerBrowserPluginElement(viewType) {
     var unused = this.nonExistentAttribute;
   };
 
-  proto.attributeChangedCallback = function(name, oldValue, newValue) {
-    var internal = privates(this).internal;
-    if (!internal) {
-      return;
-    }
-    internal.handleBrowserPluginAttributeMutation(name, oldValue, newValue);
-  };
+  if (!isSitePerProcess) {
+    proto.attributeChangedCallback = function(name, oldValue, newValue) {
+      var internal = privates(this).internal;
+      if (!internal) {
+        return;
+      }
+      internal.handleBrowserPluginAttributeMutation(name, oldValue, newValue);
+    };
+  }
 
+  var options = {prototype: proto};
+  options.extends = isSitePerProcess ? 'iframe' : 'object';
   GuestViewContainer[viewType + 'BrowserPlugin'] =
-      DocumentNatives.RegisterElement(viewType + 'browserplugin',
-                                      {extends: 'object', prototype: proto});
+      DocumentNatives.RegisterElement(viewType + 'browserplugin', options);
 
   delete proto.createdCallback;
   delete proto.attachedCallback;