Move RenderViewHostManager from WebContents to FrameTreeNode.

content/browser/web_contents/web_contents_impl.h

Index: content/browser/web_contents/web_contents_impl.h
diff --git a/content/browser/web_contents/web_contents_impl.h b/content/browser/web_contents/web_contents_impl.h
index a4530af21e2ff8e8d758210db25ecf866c9e5d42..7488ea18aea21e8e47491d140a12a2edabc45da5 100644
--- a/content/browser/web_contents/web_contents_impl.h
+++ b/content/browser/web_contents/web_contents_impl.h
@@ -758,6 +758,10 @@ class CONTENT_EXPORT WebContentsImpl
 
   void SetEncoding(const std::string& encoding);
 
+  // TODO(creis): This should take in a FrameTreeNode to know which node's
+  // render manager to return.  For now, we just return the root's.
+  RenderViewHostManager* GetRenderManager() const;
+
   RenderViewHostImpl* GetRenderViewHostImpl();
 
   // Removes browser plugin embedder if there is one.
@@ -804,7 +808,7 @@ class CONTENT_EXPORT WebContentsImpl
   DestructionObservers destruction_observers_;
 
   // A list of observers notified when page state changes. Weak references.
-  // This MUST be listed above render_manager_ since at destruction time the
+  // This MUST be listed above frame_tree_ since at destruction time the
   // latter might cause RenderViewHost's destructor to call us and we might use
   // the observer list then.
   ObserverList<WebContentsObserver> observers_;
@@ -826,10 +830,7 @@ class CONTENT_EXPORT WebContentsImpl
       PowerSaveBlockerMap;
   PowerSaveBlockerMap power_save_blockers_;
 
-  // Manages creation and swapping of render views.
-  RenderViewHostManager render_manager_;
-
-  // The frame tree structure of the current page.
+  // Manages the frame tree of the page and process swaps in each node.
   FrameTree frame_tree_;
 
 #if defined(OS_ANDROID)