Enable ServerTiming support

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

Index: third_party/WebKit/Source/core/timing/PerformanceBase.h
diff --git a/third_party/WebKit/Source/core/timing/PerformanceBase.h b/third_party/WebKit/Source/core/timing/PerformanceBase.h
index bf0c5848ce1bd18520d140d4a05638f37679d4f6..e80c80088391b0cbd77d54b5566cca865b324fe2 100644
--- a/third_party/WebKit/Source/core/timing/PerformanceBase.h
+++ b/third_party/WebKit/Source/core/timing/PerformanceBase.h
@@ -111,6 +111,12 @@ class CORE_EXPORT PerformanceBase : public EventTargetWithInlineData {
 
   void addResourceTiming(const ResourceTimingInfo&);
 
+  enum class ShouldAddToBuffer {
+    Always,
+    Never,
+  };
+  void addServerTiming(const ResourceResponse&, const ShouldAddToBuffer&);
+
   void notifyNavigationTimingToObservers();
 
   void addFirstPaintTiming(double startTime);
@@ -171,6 +177,7 @@ class CORE_EXPORT PerformanceBase : public EventTargetWithInlineData {
   unsigned m_frameTimingBufferSize;
   PerformanceEntryVector m_resourceTimingBuffer;
   unsigned m_resourceTimingBufferSize;
+  PerformanceEntryVector m_serverTimingBuffer;
   Member<PerformanceEntry> m_navigationTiming;
   Member<UserTiming> m_userTiming;