[Cross-Site Isolation] Migrate entire MediaStream verticals to be per-RenderFrame.

content/browser/media/capture/web_contents_tracker.h

 // Copyright (c) 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.
 //
-// Given a starting render_process_id and render_view_id, the WebContentsTracker
-// tracks RenderViewHost instance swapping during the lifetime of a WebContents
-// instance.  This is used when mirroring tab video and audio so that user
-// navigations, crashes, etc., during a tab's lifetime allow the capturing code
-// to remain active on the current/latest RenderView.
+// Given a starting render_process_id and main_render_frame_id, the
+// WebContentsTracker tracks RenderViewHost instance swapping during the
+// lifetime of a WebContents instance.  This is used when mirroring tab video
+// and audio so that user navigations, crashes, etc., during a tab's lifetime
+// allow the capturing code to remain active on the current/latest RenderView.
+//
+// TODO(miu): In a soon upcoming change, the cross-site isolation migration of
+// this code will be completed such that the main RenderFrameHost is tracked
+// instead of the RenderViewHost.
 //
 // Threading issues: Start(), Stop() and the ChangeCallback are invoked on the
 // same thread.  This can be any thread, and the decision is locked-in by
 // WebContentsTracker when Start() is called.
 
 #ifndef CONTENT_BROWSER_MEDIA_CAPTURE_WEB_CONTENTS_TRACKER_H_
 #define CONTENT_BROWSER_MEDIA_CAPTURE_WEB_CONTENTS_TRACKER_H_
 
 #include "base/callback.h"
 #include "base/memory/ref_counted.h"
@@ skipping 12 matching lines @@
  public:
   WebContentsTracker();
 
   // Callback for whenever the target is swapped.  The callback is also invoked
   // with both arguments set to MSG_ROUTING_NONE to indicate tracking will not
   // continue (i.e., the WebContents instance was not found or has been
   // destroyed).
   typedef base::Callback<void(int render_process_id, int render_view_id)>
       ChangeCallback;
 
-  // Start tracking.  The last-known |render_process_id| and |render_view_id|
-  // are provided, and the given callback is invoked asynchronously one or more
-  // times.  The callback will be invoked on the same thread calling Start().
-  virtual void Start(int render_process_id, int render_view_id,
+  // Start tracking.  The last-known |render_process_id| and
+  // |main_render_frame_id| are provided, and the given callback is invoked
+  // asynchronously one or more times.  The callback will be invoked on the same
+  // thread calling Start().
+  virtual void Start(int render_process_id, int main_render_frame_id,
                      const ChangeCallback& callback);
 
   // Stop tracking.  Once this method returns, the callback is guaranteed not to
   // be invoked again.
   virtual void Stop();
 
  protected:
   friend class base::RefCountedThreadSafe<WebContentsTracker>;
   virtual ~WebContentsTracker();
 
  private:
   // Reads the render_process_id/render_view_id from the current WebContents
   // instance and then invokes the callback.
   void OnWebContentsChangeEvent();
 
   // Called on the thread that Start()/Stop() are called on, check whether the
   // callback is still valid and, if so, invoke it.
   void MaybeDoCallback(int render_process_id, int render_view_id);
 
   // Look-up the current WebContents instance associated with the given
-  // |render_process_id| and |render_view_id| and begin observing it.
+  // |render_process_id| and |main_render_frame_id| and begin observing it.
   void LookUpAndObserveWebContents(int render_process_id,
-                                   int render_view_id);
+                                   int main_render_frame_id);
 
   // WebContentsObserver overrides to react to events of interest.
   virtual void RenderViewReady() OVERRIDE;
   virtual void AboutToNavigateRenderView(RenderViewHost* render_view_host)
       OVERRIDE;
   virtual void DidNavigateMainFrame(const LoadCommittedDetails& details,
                                     const FrameNavigateParams& params) OVERRIDE;
   virtual void WebContentsDestroyed() OVERRIDE;
 
   scoped_refptr<base::MessageLoopProxy> message_loop_;
   ChangeCallback callback_;
 
   DISALLOW_COPY_AND_ASSIGN(WebContentsTracker);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_MEDIA_CAPTURE_WEB_CONTENTS_TRACKER_H_