Add NavigationToFirstContentfulPaint UMA for ServiceWorker controlled pages.

third_party/WebKit/Source/web/WebPerformance.cpp

 /*
  * Copyright (C) 2010 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 57 matching lines @@
 double WebPerformance::navigationStart() const
 {
     return millisecondsToSeconds(m_private->timing()->navigationStart());
 }
 
 double WebPerformance::unloadEventEnd() const
 {
     return millisecondsToSeconds(m_private->timing()->unloadEventEnd());
 }
 
+double WebPerformance::workerStart() const
+{
+    return millisecondsToSeconds(m_private->timing()->workerStart());
+}
+
 double WebPerformance::redirectStart() const
 {
     return millisecondsToSeconds(m_private->timing()->redirectStart());
 }
 
 double WebPerformance::redirectEnd() const
 {
     return millisecondsToSeconds(m_private->timing()->redirectEnd());
 }
 
@@ skipping 127 matching lines @@
 {
 }
 
 WebPerformance& WebPerformance::operator=(Performance*performance)
 {
     m_private = performance;
     return *this;
 }
 
 } // namespace blink