Refactor the loading tracking logic in WebContentsImpl.

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"
@@ skipping 12 matching lines @@
 class FrameTree;
 class Navigator;
 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:
-
   FrameTreeNode(FrameTree* frame_tree,
                 Navigator* navigator,
                 RenderFrameHostDelegate* render_frame_delegate,
                 RenderViewHostDelegate* render_view_delegate,
                 RenderWidgetHostDelegate* render_widget_delegate,
                 RenderFrameHostManager::Delegate* manager_delegate,
                 const std::string& name);
 
   ~FrameTreeNode();
 
@@ skipping 54 matching lines @@
   }
 
   bool HasSameOrigin(const FrameTreeNode& node) const {
     return replication_state_.origin.IsSameAs(node.replication_state_.origin);
   }
 
   const FrameReplicationState& current_replication_state() const {
     return replication_state_;
   }
 
-  void set_is_loading(bool is_loading) {
-    is_loading_ = is_loading;
-  }
-  bool is_loading() const {
-    return is_loading_;
-  }
-
   RenderFrameHostImpl* current_frame_host() const {
     return render_manager_.current_frame_host();
   }
 
   bool IsDescendantOf(FrameTreeNode* other) const;
 
+  // Returns true if either the current or pending RenderFrameHost from the

[nasko, 2015/02/26 23:30:33]

nit: Let's avoid putting implementation details in the comment. It somehow
figures out whether the current node is in a loading state : ).

[Fabrice (no longer in Chrome), 2015/02/27 17:45:25]

Acknowledged.

+  // associated RenderFrameHostManager is loading.
+  bool IsLoading() const;
+
+  // Returns the loading progress of the current RenderFrameHost from the
+  // associated RenderFrameHostManager.
+  double GetLoadingProgress() const;
+
  private:
   void set_parent(FrameTreeNode* parent) { parent_ = parent; }
 
   // The next available browser-global FrameTreeNode ID.
   static int64 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_;
 
   // 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
+  // That's currently necessary so that RenderFrameHostImpl's destructor can
   // call GetProcess.
   RenderFrameHostManager 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 parent node of this frame. NULL if this node is the root or if it has
   // not yet been attached to the frame tree.
   FrameTreeNode* parent_;
 
   // The immediate children of this specific frame.
   ScopedVector<FrameTreeNode> children_;
 
   // 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_;
 
   // Track information that needs to be replicated to processes that have
   // proxies for this frame.
   FrameReplicationState replication_state_;
 
-  // Boolean value indicating whether the frame is in the process of loading
-  // a document or not. In cross-process transfer navigation the DidStartLoading
-  // message is received from both existing RenderFrame and from the pending
-  // RenderFrame. However, there will be only one DidStopLoading message sent by
-  // the pending-which-becomes-current RenderFrame. Since both renderers belong
-  // to the FrameTreeNode, it is better to ask it about the loading status than
-  // RenderFrameHost or using a counter to balance the events out.
-  bool is_loading_;
-
   DISALLOW_COPY_AND_ASSIGN(FrameTreeNode);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_FRAME_HOST_FRAME_TREE_NODE_H_