Enforce FirstContentfulPaint <= FirstMeaningfulPaint

third_party/WebKit/Source/core/paint/FirstMeaningfulPaintDetector.cpp

Index: third_party/WebKit/Source/core/paint/FirstMeaningfulPaintDetector.cpp
diff --git a/third_party/WebKit/Source/core/paint/FirstMeaningfulPaintDetector.cpp b/third_party/WebKit/Source/core/paint/FirstMeaningfulPaintDetector.cpp
index 5b52320b918b4e7a613936f0899f21c255453a3b..9fca4136977ee48f1cbc383fcf7596b21f0748de 100644
--- a/third_party/WebKit/Source/core/paint/FirstMeaningfulPaintDetector.cpp
+++ b/third_party/WebKit/Source/core/paint/FirstMeaningfulPaintDetector.cpp
@@ -122,8 +122,12 @@ void FirstMeaningfulPaintDetector::networkStableTimerFired(TimerBase*) {
       !m_paintTiming->firstContentfulPaint())
     return;
 
-  if (m_provisionalFirstMeaningfulPaint)
-    m_paintTiming->setFirstMeaningfulPaint(m_provisionalFirstMeaningfulPaint);
+  if (m_provisionalFirstMeaningfulPaint) {
+    // Enforce FirstContentfulPaint <= FirstMeaningfulPaint.
+    double timestamp = std::max(m_provisionalFirstMeaningfulPaint,
+                                m_paintTiming->firstContentfulPaint());
+    m_paintTiming->setFirstMeaningfulPaint(timestamp);
+  }
   m_state = Reported;
 }