Remove the is_loading_ field from WebContentsImpl

content/browser/frame_host/frame_tree.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_H_
 #define CONTENT_BROWSER_FRAME_HOST_FRAME_TREE_H_
 
 #include <stdint.h>
 
 #include <string>
@@ skipping 23 matching lines @@
 // it to serve as an anchor for state that needs to persist across top-level
 // page navigations.
 //
 // TODO(ajwong): Move NavigationController ownership to the main frame
 // FrameTreeNode. Possibly expose access to it from here.
 //
 // This object is only used on the UI thread.
 class CONTENT_EXPORT FrameTree {
  public:
   class NodeRange;
+  class ConstNodeRange;
 
   class CONTENT_EXPORT NodeIterator {
    public:
     ~NodeIterator();
 
     NodeIterator& operator++();
 
     bool operator==(const NodeIterator& rhs) const;
     bool operator!=(const NodeIterator& rhs) const { return !(*this == rhs); }
 
@@ skipping 16 matching lines @@
 
    private:
     friend class FrameTree;
 
     NodeRange(FrameTree* tree, FrameTreeNode* node_to_skip);
 
     FrameTree* const tree_;
     FrameTreeNode* const node_to_skip_;
   };
 
+  class CONTENT_EXPORT ConstNodeIterator {
+   public:
+    ~ConstNodeIterator();
+
+    ConstNodeIterator& operator++();
+
+    bool operator==(const ConstNodeIterator& rhs) const;
+    bool operator!=(const ConstNodeIterator& rhs) const {
+      return !(*this == rhs);
+    }
+
+    const FrameTreeNode* operator*() { return current_node_; }
+
+   private:
+    friend class ConstNodeRange;
+
+    ConstNodeIterator(const FrameTreeNode* starting_node);
+
+    const FrameTreeNode* current_node_;
+    std::queue<const FrameTreeNode*> queue_;
+  };
+
+  class CONTENT_EXPORT ConstNodeRange {
+   public:
+    ConstNodeIterator begin();
+    ConstNodeIterator end();
+
+   private:
+    friend class FrameTree;
+
+    ConstNodeRange(const FrameTree* tree);
+
+    const FrameTree* const tree_;
+  };
+
   // Each FrameTreeNode will default to using the given |navigator| for
   // navigation tasks in the frame.
   // A set of delegates are remembered here so that we can create
   // RenderFrameHostManagers.
   // TODO(creis): This set of delegates will change as we move things to
   // Navigator.
   FrameTree(Navigator* navigator,
             RenderFrameHostDelegate* render_frame_delegate,
             RenderViewHostDelegate* render_view_delegate,
             RenderWidgetHostDelegate* render_widget_delegate,
@@ skipping 12 matching lines @@
   // Returns the first frame in this tree with the given |name|, or the main
   // frame if |name| is empty.
   // Note that this does NOT support pseudo-names like _self, _top, and _blank,
   // nor searching other FrameTrees (unlike blink::WebView::findFrameByName).
   FrameTreeNode* FindByName(const std::string& name);
 
   // Returns a range to iterate over all FrameTreeNodes in the frame tree in
   // breadth-first traversal order.
   NodeRange Nodes();
 
+  // Returns a range to iterate over all FrameTreeNodes in the frame tree in
+  // breadth-first traversal order. All FrameTreeNodes returned will be const.
+  ConstNodeRange ConstNodes() const;
+
   // Adds a new child frame to the frame tree. |process_id| is required to
   // disambiguate |new_routing_id|, and it must match the process of the
   // |parent| node. Otherwise no child is added and this method returns false.
   bool AddFrame(FrameTreeNode* parent,
                 int process_id,
                 int new_routing_id,
                 blink::WebTreeScopeType scope,
                 const std::string& frame_name,
                 blink::WebSandboxFlags sandbox_flags,
                 const blink::WebFrameOwnerProperties& frame_owner_properties);
@@ skipping 58 matching lines @@
   // Updates the overall load progress and notifies the WebContents.
   void UpdateLoadProgress();
 
   // Returns this FrameTree's total load progress.
   double load_progress() { return load_progress_; }
 
   // Resets the load progress on all nodes in this FrameTree.
   void ResetLoadProgress();
 
   // Returns true if at least one of the nodes in this FrameTree is loading.
-  bool IsLoading();
+  bool IsLoading() const;
 
   // Set page-level focus in all SiteInstances involved in rendering
   // this FrameTree, not including the current main frame's
   // SiteInstance. The focus update will be sent via the main frame's proxies
   // in those SiteInstances.
   void ReplicatePageFocus(bool is_focused);
 
   // Updates page-level focus for this FrameTree in the subframe renderer
   // identified by |instance|.
   void SetPageFocus(SiteInstance* instance, bool is_focused);
@@ skipping 45 matching lines @@
 
   // Overall load progress.
   double load_progress_;
 
   DISALLOW_COPY_AND_ASSIGN(FrameTree);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_FRAME_HOST_FRAME_TREE_H_