Use FrameTreeNode ID as frameId in extension APIs

content/public/browser/render_frame_host.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_PUBLIC_BROWSER_RENDER_FRAME_HOST_H_
 #define CONTENT_PUBLIC_BROWSER_RENDER_FRAME_HOST_H_
 
 #include <string>
 
 #include "base/callback_forward.h"
@@ skipping 17 matching lines @@
 class SiteInstance;
 
 // The interface provides a communication conduit with a frame in the renderer.
 class CONTENT_EXPORT RenderFrameHost : public IPC::Listener,
                                        public IPC::Sender {
  public:
   // Returns the RenderFrameHost given its ID and the ID of its render process.
   // Returns nullptr if the IDs do not correspond to a live RenderFrameHost.
   static RenderFrameHost* FromID(int render_process_id, int render_frame_id);
 
+  // Returns the RenderFrameHost that hosts the frame identified by the given
+  // FrameTreeNode ID. Returns nullptr if not found.
+  static RenderFrameHost* FromFrameTreeNodeID(int frame_tree_node_id);
+
   // Globally allows for injecting JavaScript into the main world. This feature
   // is present only to support Android WebView and must not be used in other
   // configurations.
   static void AllowInjectingJavaScriptForAndroidWebView();
 
   // Returns a RenderFrameHost given its accessibility tree ID.
   static RenderFrameHost* FromAXTreeID(int ax_tree_id);
 
   ~RenderFrameHost() override {}
 
   // Returns the route id for this frame.
   virtual int GetRoutingID() = 0;
 
   // Returns the accessibility tree ID for this RenderFrameHost.
   virtual int GetAXTreeID() = 0;
 
   // Returns the SiteInstance grouping all RenderFrameHosts that have script
   // access to this RenderFrameHost, and must therefore live in the same
   // process.
   virtual SiteInstance* GetSiteInstance() = 0;
 
   // Returns the process for this frame.
   virtual RenderProcessHost* GetProcess() = 0;
 
   // Returns the current RenderFrameHost of the parent frame, or nullptr if
   // there is no parent. The result may be in a different process than the
   // current RenderFrameHost.
   virtual RenderFrameHost* GetParent() = 0;
 
+  // Returns the RenderFrameHost for the given FrameTreeNode ID if it is the

[Charlie Reis, 2015/10/30 23:25:09]

nit: the current RenderFrameHost
(The same FrameTreeNode ID can refer to different RenderFrameHosts at different
times, due to cross-process navigations.)

[robwu, 2015/11/02 19:08:34]

Done.

+  // frame itself or a child of this frame.

[Charlie Reis, 2015/10/30 23:25:09]

nit: or an immediate child

(Is this what you intended?  I'm not sure about the use cases.  If you just need
to find any frame in a given FrameTree, the method might belong in WebContents
instead.)

[robwu, 2015/10/31 00:10:45]

My use case is finding a frame within a given tab, so moving to a WebContents
sounds good.

[robwu, 2015/11/02 19:08:34]

Done.

+  virtual RenderFrameHost* FindByFrameTreeNodeID(int frame_tree_node_id) = 0;
+
+  // Returns the FrameTreeNode ID for this frame.
+  virtual int GetFrameTreeNodeID() = 0;
+
   // Returns the assigned name of the frame, the name of the iframe tag
   // declaring it. For example, <iframe name="framename">[...]</iframe>. It is
   // quite possible for a frame to have no name, in which case GetFrameName will
   // return an empty string.
   virtual const std::string& GetFrameName() = 0;
 
   // Returns true if the frame is out of process.
   virtual bool IsCrossProcessSubframe() = 0;
 
   // Returns the last committed URL of the frame.
@@ skipping 73 matching lines @@
 
  private:
   // This interface should only be implemented inside content.
   friend class RenderFrameHostImpl;
   RenderFrameHost() {}
 };
 
 }  // namespace content
 
 #endif  // CONTENT_PUBLIC_BROWSER_RENDER_FRAME_HOST_H_