Adding histograms showing fraction of page load times

chrome/browser/profiles/profile_io_data.h

Index: chrome/browser/profiles/profile_io_data.h
===================================================================
--- chrome/browser/profiles/profile_io_data.h	(revision 147972)
+++ chrome/browser/profiles/profile_io_data.h	(working copy)
@@ -30,6 +30,7 @@
 class TransportSecurityPersister;
 
 namespace chrome_browser_net {
+class CacheStats;
 class HttpServerPropertiesManager;
 class ResourcePrefetchPredictorObserver;
 }
@@ -201,6 +202,10 @@
   // Called when the profile is destroyed.
   void ShutdownOnUIThread();
 
+  // Returns the CacheStats object to be used for this profile
+  // (may be NULL for OTR profiles).
+  virtual chrome_browser_net::CacheStats* GetCacheStats() const;
+
   BooleanPrefMember* enable_referrers() const {
     return &enable_referrers_;
   }