Introduce browser side FrameTreeNodeBlameContext

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 <stddef.h>
 
 #include <memory>
 #include <string>
 #include <vector>
 
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
+#include "content/browser/frame_host/frame_tree_node_blame_context.h"
 #include "content/browser/frame_host/render_frame_host_impl.h"
 #include "content/browser/frame_host/render_frame_host_manager.h"
 #include "content/common/content_export.h"
 #include "content/common/frame_replication_state.h"
 #include "third_party/WebKit/public/web/WebFrameOwnerProperties.h"
 #include "url/gurl.h"
 #include "url/origin.h"
 
 namespace content {
 
@@ skipping 232 matching lines @@
 
   // Called when this node becomes focused.  Updates the node's last focused
   // time and notifies observers.
   void DidFocus();
 
   // Called when the user closed the modal dialogue for BeforeUnload and
   // cancelled the navigation. This should stop any load happening in the
   // FrameTreeNode.
   void BeforeUnloadCanceled();
 
+  FrameTreeNodeBlameContext* blame_context() const { return blame_context_; }

[Charlie Reis, 2016/04/20 16:58:58]

These all need comments, because it's not obvious what "blame context" means in
relation to the core FrameTreeNode logic.

[Xiaocheng, 2016/04/21 08:01:32]

Done.

+
+  void InitializeBlameContext();
+
  private:
   class OpenerDestroyedObserver;
 
   void set_parent(FrameTreeNode* parent) { parent_ = parent; }
 
-  void TraceSnapshot() const;
-
   // The next available browser-global FrameTreeNode ID.
   static int next_frame_tree_node_id_;
 
   // The FrameTree that owns us.
   FrameTree* frame_tree_;  // not owned.
 
   // The Navigator object responsible for managing navigations at this node
   // of the frame tree.
   scoped_refptr<Navigator> navigator_;
 
@@ skipping 55 matching lines @@
   // PlzNavigate
   // Owns an ongoing NavigationRequest until it is ready to commit. It will then
   // be reset and a RenderFrameHost will be responsible for the navigation.
   std::unique_ptr<NavigationRequest> navigation_request_;
 
   // List of objects observing this FrameTreeNode.
   base::ObserverList<Observer> observers_;
 
   base::TimeTicks last_focus_time_;
 
+  FrameTreeNodeBlameContext* blame_context_; // Not owned.
+
   DISALLOW_COPY_AND_ASSIGN(FrameTreeNode);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_FRAME_HOST_FRAME_TREE_NODE_H_