Add timer to OffscreenCanvas's commit API

third_party/WebKit/Source/modules/offscreencanvas2d/OffscreenCanvasRenderingContext2D.cpp

Index: third_party/WebKit/Source/modules/offscreencanvas2d/OffscreenCanvasRenderingContext2D.cpp
diff --git a/third_party/WebKit/Source/modules/offscreencanvas2d/OffscreenCanvasRenderingContext2D.cpp b/third_party/WebKit/Source/modules/offscreencanvas2d/OffscreenCanvasRenderingContext2D.cpp
index c6cd1197505663e17cd734771ec32f7aaebe12e6..b35ffa2c3ad31c1e7f0e6f57af726f79945c63cb 100644
--- a/third_party/WebKit/Source/modules/offscreencanvas2d/OffscreenCanvasRenderingContext2D.cpp
+++ b/third_party/WebKit/Source/modules/offscreencanvas2d/OffscreenCanvasRenderingContext2D.cpp
@@ -14,6 +14,7 @@
 #include "platform/graphics/UnacceleratedImageBufferSurface.h"
 #include "platform/graphics/gpu/AcceleratedImageBufferSurface.h"
 #include "wtf/Assertions.h"
+#include "wtf/CurrentTime.h"
 
 #define UNIMPLEMENTED ASSERT_NOT_REACHED
 
@@ -55,9 +56,10 @@ void OffscreenCanvasRenderingContext2D::commit(ExceptionState& exceptionState) {
                                      "canvas element.");
     return;
   }
+  double commitStartTime = WTF::monotonicallyIncreasingTime();
   RefPtr<StaticBitmapImage> image = this->transferToStaticBitmapImage();
   getOffscreenCanvas()->getOrCreateFrameDispatcher()->dispatchFrame(
-      std::move(image));
+      std::move(image), commitStartTime);
 }
 
 // BaseRenderingContext2D implementation