first-paint and first-contentful paint

third_party/WebKit/Source/core/timing/PerformanceBase.cpp

Index: third_party/WebKit/Source/core/timing/PerformanceBase.cpp
diff --git a/third_party/WebKit/Source/core/timing/PerformanceBase.cpp b/third_party/WebKit/Source/core/timing/PerformanceBase.cpp
index 377a1aed2fef0359fd57b733cf2bb90313c3c678..2eaa02a0132814542de106fb669ccdbbe0b93f00 100644
--- a/third_party/WebKit/Source/core/timing/PerformanceBase.cpp
+++ b/third_party/WebKit/Source/core/timing/PerformanceBase.cpp
@@ -103,9 +103,11 @@ PerformanceEntryVector PerformanceBase::getEntriesByType(
   switch (type) {
     case PerformanceEntry::Invalid:
       return entries;
+    case PerformanceEntry::Paint:

[panicker, 2016/12/05 20:51:23]

Nit: add another comment here instead of adding to list below.

[sunjian, 2016/12/07 21:55:44]

Done.

     case PerformanceEntry::LongTask:
-      // Unsupported for LongTask. Per the spec, Long task entries can only be
-      // accessed via Performance Observer. No separate buffer is maintained.
+      // Unsupported for LongTask or Paint. Per the spec, Long task entries and
+      // Paint entries can only be accessed via Performance Observer.
+      // No separate buffer is maintained.
       return entries;
     case PerformanceEntry::Resource:
       for (const auto& resource : m_resourceTimingBuffer)
@@ -355,6 +357,15 @@ void PerformanceBase::addNavigationTiming(LocalFrame* frame) {
   notifyObserversOfEntry(*m_navigationTiming);
 }
 
+void PerformanceBase::addPaintTiming(PerformancePaintTiming::PaintType type,
+                                     double startTime) {
+  if (!RuntimeEnabledFeatures::performancePaintTimingEnabled())
+    return;
+  PerformanceEntry* entry = new PerformancePaintTiming(
+      type, monotonicTimeToDOMHighResTimeStamp(startTime));
+  notifyObserversOfEntry(*entry);
+}
+
 void PerformanceBase::addResourceTimingBuffer(PerformanceEntry& entry) {
   m_resourceTimingBuffer.append(&entry);