Remove the is_loading_ field from WebContentsImpl

content/browser/frame_host/frame_tree.cc

 // 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.
 
 #include "content/browser/frame_host/frame_tree.h"
 
 #include <stddef.h>
 
 #include <queue>
 #include <utility>
@@ skipping 427 matching lines @@
 
   // Notify the WebContents.
   root_->navigator()->GetDelegate()->DidChangeLoadProgress();
 }
 
 void FrameTree::ResetLoadProgress() {
   ForEach(base::Bind(&ResetNodeLoadProgress));
   load_progress_ = 0.0;
 }
 
-bool FrameTree::IsLoading() {
+bool FrameTree::IsLoading() const {
   bool is_loading = false;
   ForEach(base::Bind(&IsNodeLoading, &is_loading));
   return is_loading;
 }
 
 void FrameTree::ReplicatePageFocus(bool is_focused) {
   std::set<SiteInstance*> frame_tree_site_instances;
   ForEach(base::Bind(&CollectSiteInstances, &frame_tree_site_instances));
 
   // Send the focus update to main frame's proxies in all SiteInstances of
@@ skipping 11 matching lines @@
   // This is only used to set page-level focus in cross-process subframes, and
   // requests to set focus in main frame's SiteInstance are ignored.
   if (instance != root_manager->current_frame_host()->GetSiteInstance()) {
     RenderFrameProxyHost* proxy =
         root_manager->GetRenderFrameProxyHost(instance);
     proxy->Send(new InputMsg_SetFocus(proxy->GetRoutingID(), is_focused));
   }
 }
 
 }  // namespace content