Extract the element implementation logic to function mods in <webview>.

extensions/renderer/resources/guest_view/guest_view_iframe.js

+// Copyright 2015 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.
+
+// --site-per-process overrides for guest_view.js.
+
+var GuestView = require('guestView').GuestView;
+var GuestViewImpl = require('guestView').GuestViewImpl;
+var GuestViewInternalNatives = requireNative('guest_view_internal');
+var ResizeEvent = require('guestView').ResizeEvent;
+
+var getIframeContentWindow = function(viewInstanceId) {
+  var view = GuestViewInternalNatives.GetViewFromID(viewInstanceId);
+  if (!view)
+    return null;
+
+  var internalIframeElement = privates(view).internalElement;
+  if (internalIframeElement)
+    return internalIframeElement.contentWindow;
+
+  return null;
+};
+
+// Internal implementation of attach().
+GuestViewImpl.prototype.attachImpl$ = function(
+    internalInstanceId, viewInstanceId, attachParams, callback) {
+  // Check the current state.
+  if (!this.checkState('attach')) {
+    this.handleCallback(callback);
+    return;
+  }
+
+  // Callback wrapper function to store the contentWindow from the attachGuest()
+  // callback, handle potential attaching failure, register an automatic detach,
+  // and advance the queue.
+  var callbackWrapper = function(callback, contentWindow) {
+    // Check if attaching failed.
+    contentWindow = getIframeContentWindow(viewInstanceId);
+    if (!contentWindow) {
+      this.state = GuestViewImpl.GuestState.GUEST_STATE_CREATED;
+      this.internalInstanceId = 0;
+    } else {
+      // Only update the contentWindow if attaching is successful.
+      this.contentWindow = contentWindow;
+    }
+
+    this.handleCallback(callback);
+  };
+
+  attachParams['instanceId'] = viewInstanceId;
+  var contentWindow = getIframeContentWindow(viewInstanceId);
+  // TODO(lazyboy): Call binding function to attach this guest.
+  // |contentWindow| should be used to retrieve the RenderFrame in cpp.
+
+  this.internalInstanceId = internalInstanceId;
+  this.state = GuestViewImpl.GuestState.GUEST_STATE_ATTACHED;
+
+  // Detach automatically when the container is destroyed.
+  GuestViewInternalNatives.RegisterDestructionCallback(
+      internalInstanceId, this.weakWrapper(function() {
+    if (this.state != GuestViewImpl.GuestState.GUEST_STATE_ATTACHED ||
+        this.internalInstanceId != internalInstanceId) {
+      return;
+    }
+
+    this.internalInstanceId = 0;
+    this.state = GuestViewImpl.GuestState.GUEST_STATE_CREATED;
+  }, viewInstanceId));
+};
+
+// Internal implementation of create().
+GuestViewImpl.prototype.createImpl$ = function(createParams, callback) {
+  // Check the current state.
+  if (!this.checkState('create')) {
+    this.handleCallback(callback);
+    return;
+  }
+
+  // Callback wrapper function to store the guestInstanceId from the
+  // createGuest() callback, handle potential creation failure, and advance the
+  // queue.
+  var callbackWrapper = function(callback, guestInfo) {
+    this.id = guestInfo.id;
+
+    // Check if creation failed.
+    if (this.id === 0) {
+      this.state = GuestViewImpl.GuestState.GUEST_STATE_START;
+      this.contentWindow = null;
+    }
+
+    ResizeEvent.addListener(this.callOnResize, {instanceId: this.id});
+    this.handleCallback(callback);
+  };
+
+  this.sendCreateRequest(createParams, callbackWrapper.bind(this, callback));
+
+  this.state = GuestViewImpl.GuestState.GUEST_STATE_CREATED;
+};