Blink changes to record interest rects for http://w3c.github.io/frame-timing/

Source/core/timing/Performance.idl

Index: Source/core/timing/Performance.idl
diff --git a/Source/core/timing/Performance.idl b/Source/core/timing/Performance.idl
index fbbfbe94e758bc02eaddf73fa003ed2786ac0b79..2c04c8a2c45554cb3b5e7cffbc466fb768024c9b 100644
--- a/Source/core/timing/Performance.idl
+++ b/Source/core/timing/Performance.idl
@@ -42,8 +42,13 @@ interface Performance : EventTarget {
     [MeasureAs=PrefixedPerformanceClearResourceTimings] void webkitClearResourceTimings();
     [MeasureAs=PrefixedPerformanceSetResourceTimingBufferSize] void webkitSetResourceTimingBufferSize(unsigned long maxSize);
 
+    [MeasureAs=PerformanceFrameTiming,RuntimeEnabled=FrameTimingSupport] void clearFrameTimings();
+    [MeasureAs=PerformanceFrameTiming,RuntimeEnabled=FrameTimingSupport] void setFrameTimingBufferSize(unsigned long maxSize);
+
     attribute EventHandler onwebkitresourcetimingbufferfull;
 
+    [RuntimeEnabled=FrameTimingSupport] attribute EventHandler onframetimingbufferfull;
+
     // See http://www.w3.org/TR/2012/CR-user-timing-20120726/
     [RaisesException,MeasureAs=UnprefixedUserTiming] void mark(DOMString markName);
     [MeasureAs=UnprefixedUserTiming] void clearMarks(optional DOMString markName = null);