[DRAFT] Create RenderFrameHostManager.

content/browser/frame_host/frame_tree_node.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_BROWSER_FRAME_HOST_FRAME_TREE_NODE_H_
 #define CONTENT_BROWSER_FRAME_HOST_FRAME_TREE_NODE_H_
 
 #include <string>
 
 #include "base/basictypes.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/scoped_vector.h"
+#include "content/browser/frame_host/render_view_host_manager.h"
 #include "content/common/content_export.h"
 #include "url/gurl.h"
 
 namespace content {
 
 class RenderFrameHostImpl;
 
 // When a page contains iframes, its renderer process maintains a tree structure
 // of those frames. We are mirroring this tree in the browser process. This
 // class represents a node in this tree and is a wrapper for all objects that
 // are frame-specific (as opposed to page-specific).
 class CONTENT_EXPORT FrameTreeNode {
  public:
-  static const int64 kInvalidFrameId;
-
-  FrameTreeNode(int64 frame_id, const std::string& name,
-                scoped_ptr<RenderFrameHostImpl> render_frame_host);
+  FrameTreeNode(int64 frame_tree_node_id,
+                const std::string& name,
+                RenderViewHostDelegate* render_view_delegate,
+                RenderWidgetHostDelegate* render_widget_delegate,
+                RenderViewHostManager::Delegate* manager_delegate);
   ~FrameTreeNode();
 
   void AddChild(scoped_ptr<FrameTreeNode> child);
   void RemoveChild(int64 child_id);
 
-  // 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);
-
-  void set_frame_id(int64 frame_id) {
-    DCHECK_EQ(frame_id_, kInvalidFrameId);
-    frame_id_ = frame_id;
-  }
-
-  int64 frame_id() const {
-    return frame_id_;
+  // 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_;
   }
 
   const std::string& frame_name() const {
     return frame_name_;
   }
 
   size_t child_count() const {
     return children_.size();
   }
 
   FrameTreeNode* child_at(size_t index) const {
     return children_[index];
   }
 
   const GURL& current_url() const {
     return current_url_;
   }
 
   void set_current_url(const GURL& url) {
     current_url_ = url;
   }
 
+  RenderViewHostManager* render_manager() {
+    return &render_manager_;
+  }
+
   RenderFrameHostImpl* render_frame_host() const {
-    return render_frame_host_;
+    return render_manager_.current_frame();
   }
 
  private:
-  // The unique identifier for the frame in the page.
-  int64 frame_id_;
+  // The browser-wide unique identifier for the frame in the page.
+  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.
   std::string frame_name_;
 
   // 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_;
+  // Manages creation and swapping of RenderFrameHosts for this frame.
+  RenderViewHostManager render_manager_;
 
   // 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
   // NavigationController.
   GURL current_url_;
 
   DISALLOW_COPY_AND_ASSIGN(FrameTreeNode);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_FRAME_HOST_FRAME_TREE_NODE_H_