(DEPRECATED) Send navigation_start to browser process in DidStartProvisionalLoad

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

Index: third_party/WebKit/Source/core/loader/DocumentLoadTiming.cpp
diff --git a/third_party/WebKit/Source/core/loader/DocumentLoadTiming.cpp b/third_party/WebKit/Source/core/loader/DocumentLoadTiming.cpp
index 33f85356cf1b5a720608c174489791809809e6ee..011335672676f1c5a996ed6d478b87ddee0759fd 100644
--- a/third_party/WebKit/Source/core/loader/DocumentLoadTiming.cpp
+++ b/third_party/WebKit/Source/core/loader/DocumentLoadTiming.cpp
@@ -87,6 +87,12 @@ double DocumentLoadTiming::pseudoWallTimeToMonotonicTime(double pseudoWallTime)
 
 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);
 
@@ -98,14 +104,16 @@ void DocumentLoadTiming::markNavigationStart()
 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();
 }