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

content/browser/frame_host/frame_tree_node.h

 // Copyright 2013 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.
 
 #ifndef CONTENT_BROWSER_FRAME_HOST_FRAME_TREE_NODE_H_
 #define CONTENT_BROWSER_FRAME_HOST_FRAME_TREE_NODE_H_
 
 #include <string>
 
 #include "base/basictypes.h"
@@ skipping 21 matching lines @@
 class CONTENT_EXPORT FrameTreeNode {
  public:
   class Observer {
    public:
     // Invoked when a FrameTreeNode is being destroyed.
     virtual void OnFrameTreeNodeDestroyed(FrameTreeNode* node) {}
 
     virtual ~Observer() {}
   };
 
+  static const int kFrameTreeNodeInvalidID = -1;
+
   // Returns the FrameTreeNode with the given global |frame_tree_node_id|,
   // regardless of which FrameTree it is in.
   static FrameTreeNode* GloballyFindByID(int frame_tree_node_id);
 
   FrameTreeNode(FrameTree* frame_tree,
                 Navigator* navigator,
                 RenderFrameHostDelegate* render_frame_delegate,
                 RenderViewHostDelegate* render_view_delegate,
                 RenderWidgetHostDelegate* render_widget_delegate,
                 RenderFrameHostManager::Delegate* manager_delegate,
@@ skipping 212 matching lines @@
 
   // List of objects observing this FrameTreeNode.
   base::ObserverList<Observer> observers_;
 
   DISALLOW_COPY_AND_ASSIGN(FrameTreeNode);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_FRAME_HOST_FRAME_TREE_NODE_H_