[DRAFT] Create RenderFrameHostManager.

content/browser/frame_host/frame_tree_node.h

Index: content/browser/frame_host/frame_tree_node.h
diff --git a/content/browser/frame_host/frame_tree_node.h b/content/browser/frame_host/frame_tree_node.h
index a110ff9aab557b4155a3781c7374748293dc4373..80f49d7d3064fdc62b8186be53462441eb56eaae 100644
--- a/content/browser/frame_host/frame_tree_node.h
+++ b/content/browser/frame_host/frame_tree_node.h
@@ -26,31 +26,18 @@ class RenderFrameHostImpl;
 // are frame-specific (as opposed to page-specific).
 class CONTENT_EXPORT FrameTreeNode {
  public:
-  static const int64 kInvalidFrameId;
-
   FrameTreeNode(Navigator* navigator,
                 RenderViewHostDelegate* render_view_delegate,
                 RenderWidgetHostDelegate* render_widget_delegate,
                 RenderViewHostManager::Delegate* manager_delegate,
-                int64 frame_id,
-                const std::string& name,
-                scoped_ptr<RenderFrameHostImpl> render_frame_host);
+                const std::string& name);
 
   ~FrameTreeNode();
 
-  void AddChild(scoped_ptr<FrameTreeNode> child);
+  void AddChild(scoped_ptr<FrameTreeNode> child,
+                int render_frame_host_id);
   void RemoveChild(FrameTreeNode* child);
 
-  // Transitional API allowing the RenderFrameHost of a FrameTreeNode
-  // representing the main frame to be provided by someone else. After
-  // this is called, the FrameTreeNode no longer owns its RenderFrameHost.
-  //
-  // This should only be used for the main frame (aka root) in a frame tree.
-  //
-  // TODO(ajwong): Remove this method once the main frame RenderFrameHostImpl is
-  // no longer owned by the RenderViewHostImpl.
-  void ResetForMainFrame(RenderFrameHostImpl* new_render_frame_host);
-
   Navigator* navigator() {
     return navigator_.get();
   }
@@ -59,20 +46,13 @@ class CONTENT_EXPORT FrameTreeNode {
     return &render_manager_;
   }
 
+  // This is the browser-wide unique ID for the FrameTreeNode.  If you have a
+  // renderer-specific frame ID, you can look up the corresponding FrameTreeNode
+  // ID using RenderViewHostImpl::GetFrameTreeNodeID(frame_id).
   int64 frame_tree_node_id() const {
     return frame_tree_node_id_;
   }
 
-  // DO NOT USE.  Only used by FrameTree until we replace renderer-specific
-  // frame IDs with RenderFrameHost routing IDs.
-  void set_frame_id(int64 frame_id) {
-    DCHECK_EQ(frame_id_, kInvalidFrameId);
-    frame_id_ = frame_id;
-  }
-  int64 frame_id() const {
-    return frame_id_;
-  }
-
   const std::string& frame_name() const {
     return frame_name_;
   }
@@ -94,7 +74,7 @@ class CONTENT_EXPORT FrameTreeNode {
   }
 
   RenderFrameHostImpl* render_frame_host() const {
-    return render_frame_host_;
+    return render_manager_.current_frame();
   }
 
  private:
@@ -105,23 +85,17 @@ class CONTENT_EXPORT FrameTreeNode {
   // of the frame tree.
   scoped_refptr<Navigator> navigator_;
 
-  // Manages creation and swapping of RenderViewHosts for this frame.  This must
-  // be declared before |children_| so that it gets deleted after them.  That's
-  // currently necessary so that RenderFrameHostImpl's destructor can call
-  // GetProcess.
+  // Manages creation and swapping of RenderFrameHosts for this frame.  This
+  // must be declared before |children_| so that it gets deleted after them.
+  // That's currently necessary so that RenderFrameHostImpl's destructor can
+  // call GetProcess.
   // TODO(creis): This will become a RenderFrameHostManager, which eliminates
   // the need for |render_frame_host_| below.
   RenderViewHostManager render_manager_;
 
   // A browser-global identifier for the frame in the page, which stays stable
   // even if the frame does a cross-process navigation.
-  const int64 frame_tree_node_id_;
-
-  // The renderer-specific identifier for the frame in the page.
-  // TODO(creis): Remove this in favor of the RenderFrameHost's routing ID once
-  // we create FrameTreeNodes for all frames (even without a flag), since this
-  // value can change after cross-process navigations.
-  int64 frame_id_;
+  int64 frame_tree_node_id_;
 
   // The assigned name of the frame. This name can be empty, unlike the unique
   // name generated internally in the DOM tree.
@@ -130,22 +104,6 @@ class CONTENT_EXPORT FrameTreeNode {
   // The immediate children of this specific frame.
   ScopedVector<FrameTreeNode> children_;
 
-  // When ResetForMainFrame() is called, this is set to false and the
-  // |render_frame_host_| below is not deleted on destruction.
-  //
-  // For the mainframe, the FrameTree does not own the |render_frame_host_|.
-  // This is a transitional wart because RenderViewHostManager does not yet
-  // have the bookkeeping logic to handle creating a pending RenderFrameHost
-  // along with a pending RenderViewHost. Thus, for the main frame, the
-  // RenderViewHost currently retains ownership and the FrameTreeNode should
-  // not delete it on destruction.
-  bool owns_render_frame_host_;
-
-  // The active RenderFrameHost for this frame. The FrameTreeNode does not
-  // always own this pointer.  See comments above |owns_render_frame_host_|.
-  // TODO(ajwong): Replace with RenderFrameHostManager.
-  RenderFrameHostImpl* render_frame_host_;
-
   // Track the current frame's last committed URL, so we can estimate the
   // process impact of out-of-process iframes.
   // TODO(creis): Remove this when we can store subframe URLs in the