Revert of Remove the is_loading_ field from 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 <stddef.h>
 
 #include <string>
@@ skipping 217 matching lines @@
   // Returns true if this node is in a state where the loading progress is being
   // tracked.
   bool has_started_loading() const;
 
   // Resets this node's loading progress.
   void reset_loading_progress();
 
   // A RenderFrameHost in this node started loading.
   // |to_different_document| will be true unless the load is a fragment
   // navigation, or triggered by history.pushState/replaceState.
-  // |was_previously_loading| is false if the FrameTree was not loading before.
-  // The caller is required to provide this boolean as the delegate should only
-  // be called if the FrameTree went from non-loading to loading state.
-  // However, when it is called, the FrameTree should be in a loading state.
-  void DidStartLoading(bool to_different_document, bool was_previously_loading);
+  void DidStartLoading(bool to_different_document);
 
   // A RenderFrameHost in this node stopped loading.
   void DidStopLoading();
 
   // The load progress for a RenderFrameHost in this node was updated to
   // |load_progress|. This will notify the FrameTree which will in turn notify
   // the WebContents.
   void DidChangeLoadProgress(double load_progress);
 
   // Called when the user directed the page to stop loading. Stops all loads
   // happening in the FrameTreeNode. This method should be used with
   // FrameTree::ForEach to stop all loads in the entire FrameTree.
   bool StopLoading();
 
   // Returns the time this frame was last focused.
   base::TimeTicks last_focus_time() const { return last_focus_time_; }
 
   // 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 the loads.
-  void BeforeUnloadCanceled();
-
  private:
   class OpenerDestroyedObserver;
 
   void set_parent(FrameTreeNode* parent) { parent_ = parent; }
 
   // The next available browser-global FrameTreeNode ID.
   static int next_frame_tree_node_id_;
 
   // The FrameTree that owns us.
   FrameTree* frame_tree_;  // not owned.
@@ skipping 71 matching lines @@
   base::ObserverList<Observer> observers_;
 
   base::TimeTicks last_focus_time_;
 
   DISALLOW_COPY_AND_ASSIGN(FrameTreeNode);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_FRAME_HOST_FRAME_TREE_NODE_H_