Add time-to-network histogram considering browser side navigation

content/browser/frame_host/navigator_impl.h

Index: content/browser/frame_host/navigator_impl.h
diff --git a/content/browser/frame_host/navigator_impl.h b/content/browser/frame_host/navigator_impl.h
index 42262935862a757b5bc3cb0b6bef3ae989c75d8d..c380485f417ce0d72843a9f8ccf9b98664edbf59 100644
--- a/content/browser/frame_host/navigator_impl.h
+++ b/content/browser/frame_host/navigator_impl.h
@@ -6,6 +6,7 @@
 #define CONTENT_BROWSER_FRAME_HOST_NAVIGATOR_IMPL_H_
 
 #include "base/memory/ref_counted.h"
+#include "base/time/time.h"
 #include "content/browser/frame_host/navigation_controller_impl.h"
 #include "content/browser/frame_host/navigator.h"
 #include "content/common/content_export.h"
@@ -78,6 +79,8 @@ class CONTENT_EXPORT NavigatorImpl : public Navigator {
       RenderFrameHostImpl* render_frame_host,
       const NavigationBeforeCommitInfo& info) OVERRIDE;
 
+  virtual void LogResourceRequestTime(base::TimeTicks timestamp) OVERRIDE;
+
  private:
   virtual ~NavigatorImpl() {}
 
@@ -104,6 +107,10 @@ class CONTENT_EXPORT NavigatorImpl : public Navigator {
   // events. Can be NULL in tests.
   NavigatorDelegate* delegate_;
 
+  // The time the latest navigation request started for histogram building
+  // purposes.
+  base::TimeTicks navigation_start_time_;
+
   DISALLOW_COPY_AND_ASSIGN(NavigatorImpl);
 };