[DevTools] Expose DevToolsAgentHost for OOPIF, display it in chrome://inspect.

content/browser/frame_host/render_frame_host_impl.h

Index: content/browser/frame_host/render_frame_host_impl.h
diff --git a/content/browser/frame_host/render_frame_host_impl.h b/content/browser/frame_host/render_frame_host_impl.h
index ca442d27367f9a9f528b4d49454b85457810d156..3e14c959d2cb36daea8408de34b92d7d0677559b 100644
--- a/content/browser/frame_host/render_frame_host_impl.h
+++ b/content/browser/frame_host/render_frame_host_impl.h
@@ -209,6 +209,10 @@ class CONTENT_EXPORT RenderFrameHostImpl
   // pointer to the RenderViewHost (which inherits RenderWidgetHost).
   RenderWidgetHostImpl* GetRenderWidgetHost();
 
+  // Returns whether this frame is the root of the frame group. Frame group

[Charlie Reis, 2015/03/05 20:31:14]

This is redundant with IsCrossProcessSubframe, so we should probably just use
that instead.  (IsCrossProcessSubframe returns whether a frame is in a different
process than its parent frame, which is exactly the case that it has its own
widget and is the "root of a new frame group.")

[dgozman, 2015/03/06 16:14:14]

Done.

+  // is the continuous group of frames living in the same process.
+  bool IsFrameGroupRoot() { return GetRenderWidgetHost(); }

[nasko, 2015/03/05 15:20:48]

non-trivial method's implementations need to be in the .cc file. Also,
GetRenderWidgetHost() returns a pointer type, use "!!" to explicitly convert to
boolean.

+
   // This returns the RenderWidgetHostView that can be used to control
   // focus and visibility for this frame.
   RenderWidgetHostView* GetView();