(DEPRECATED) Send navigation_start to browser process in DidStartProvisionalLoad

third_party/WebKit/Source/core/loader/DocumentLoadTiming.cpp

 /*
  * Copyright (C) 2011 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:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 69 matching lines @@
 
 double DocumentLoadTiming::pseudoWallTimeToMonotonicTime(double pseudoWallTime) const
 {
     if (!pseudoWallTime)
         return 0.0;
     return m_referenceMonotonicTime + pseudoWallTime - m_referenceWallTime;
 }
 
 void DocumentLoadTiming::markNavigationStart()
 {
+    // Allow the embedder to override navigationStart before we record it if
+    // they have a more accurate timestamp.
+    if (m_navigationStart) {
+        ASSERT(m_referenceMonotonicTime && m_referenceWallTime);
+        return;
+    }
     TRACE_EVENT_MARK("blink.user_timing", "navigationStart");
     ASSERT(!m_navigationStart && !m_referenceMonotonicTime && !m_referenceWallTime);
 
     m_navigationStart = m_referenceMonotonicTime = monotonicallyIncreasingTime();
     m_referenceWallTime = currentTime();
     notifyDocumentTimingChanged();
 }
 
 void DocumentLoadTiming::setNavigationStart(double navigationStart)
 {
     TRACE_EVENT_MARK_WITH_TIMESTAMP("blink.user_timing", "navigationStart", navigationStart);
-    ASSERT(m_referenceMonotonicTime && m_referenceWallTime);
     m_navigationStart = navigationStart;
 
     // |m_referenceMonotonicTime| and |m_referenceWallTime| represent
     // navigationStart. When the embedder sets navigationStart (because the
     // navigation started earlied on the browser side), we need to adjust these
     // as well.
-    m_referenceWallTime = monotonicTimeToPseudoWallTime(navigationStart);
+    if (!m_referenceWallTime)
+        m_referenceWallTime = currentTime();
+    else
+        m_referenceWallTime = monotonicTimeToPseudoWallTime(navigationStart);
     m_referenceMonotonicTime = navigationStart;
     notifyDocumentTimingChanged();
 }
 
 void DocumentLoadTiming::addRedirect(const KURL& redirectingUrl, const KURL& redirectedUrl)
 {
     m_redirectCount++;
     if (!m_redirectStart) {
         setRedirectStart(m_fetchStart);
     }
@@ skipping 55 matching lines @@
 }
 
 void DocumentLoadTiming::markRedirectEnd()
 {
     TRACE_EVENT_MARK("blink.user_timing", "redirectEnd");
     m_redirectEnd = monotonicallyIncreasingTime();
     notifyDocumentTimingChanged();
 }
 
 } // namespace blink