Add time-to-network histogram considering browser side navigation

content/browser/frame_host/navigator.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_NAVIGATOR_H_
 #define CONTENT_BROWSER_FRAME_HOST_NAVIGATOR_H_
 
 #include "base/memory/ref_counted.h"
+#include "base/time/time.h"
 #include "content/common/content_export.h"
 #include "content/public/browser/navigation_controller.h"
 #include "ui/base/window_open_disposition.h"
 
 class GURL;
 struct FrameHostMsg_BeginNavigation_Params;
 struct FrameHostMsg_DidCommitProvisionalLoad_Params;
 struct FrameHostMsg_DidFailProvisionalLoadWithError_Params;
 
 namespace base {
@@ skipping 89 matching lines @@
       const GlobalRequestID& transferred_global_request_id,
       bool should_replace_current_entry,
       bool user_gesture) {}
 
   // PlzNavigate
   // Signal |render_frame_host| that a navigation is ready to commit (the
   // response to the navigation request has been received).
   virtual void CommitNavigation(RenderFrameHostImpl* render_frame_host,
                                 const NavigationBeforeCommitInfo& info) {};
 
+  // Called when the first resource request for a given navigation is executed
+  // so that it can be tracked into an histogram.
+  virtual void LogResourceRequestTime(
+    base::TimeTicks timestamp, const GURL& url) {};
+
  protected:
   friend class base::RefCounted<Navigator>;
   virtual ~Navigator() {}
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_FRAME_HOST_NAVIGATOR_H_