Expose Resource Timing methods and attribute in workers

Source/core/timing/WorkerPerformance.idl

Index: Source/core/timing/WorkerPerformance.idl
diff --git a/Source/core/timing/WorkerPerformance.idl b/Source/core/timing/WorkerPerformance.idl
index 18c8cf2337deba6ee4f27ed63fcf43276de71cc5..4352b5e1adb382c63ecbefb78e6b76255ae9225e 100644
--- a/Source/core/timing/WorkerPerformance.idl
+++ b/Source/core/timing/WorkerPerformance.idl
@@ -39,7 +39,10 @@
     [RuntimeEnabled=ServiceWorkerPerformanceTimeline] sequence<PerformanceEntry> getEntriesByType(DOMString entryType);
     [RuntimeEnabled=ServiceWorkerPerformanceTimeline] sequence<PerformanceEntry> getEntriesByName(DOMString name, optional DOMString entryType = null);
 
-    // TODO(ksakamoto): Add Resource Timing methods and attributes. crbug.com/465641
+    // See http://www.w3.org/TR/resource-timing/
+    [RuntimeEnabled=ServiceWorkerPerformanceTimeline, MeasureAs=PrefixedPerformanceClearResourceTimings] void webkitClearResourceTimings();

[tkent, 2015/06/24 07:12:00]

It's unfortunate to ship new prefixed functions...  But we don't have unprefixed
versions.

+    [RuntimeEnabled=ServiceWorkerPerformanceTimeline, MeasureAs=PrefixedPerformanceSetResourceTimingBufferSize] void webkitSetResourceTimingBufferSize(unsigned long maxSize);
+    [RuntimeEnabled=ServiceWorkerPerformanceTimeline] attribute EventHandler onwebkitresourcetimingbufferfull;
 
     // See http://www.w3.org/TR/2012/CR-user-timing-20120726/
     [RuntimeEnabled=ServiceWorkerPerformanceTimeline, RaisesException] void mark(DOMString markName);