gpu benchmarking swipe for touchpad

content/renderer/gpu/gpu_benchmarking_extension.h

Index: content/renderer/gpu/gpu_benchmarking_extension.h
diff --git a/content/renderer/gpu/gpu_benchmarking_extension.h b/content/renderer/gpu/gpu_benchmarking_extension.h
index 2b69d2b1329b1bb60d2669771ee08bf5498d25a4..6bc9c6d48acaeee83266d4202ee50d8e9d32765f 100644
--- a/content/renderer/gpu/gpu_benchmarking_extension.h
+++ b/content/renderer/gpu/gpu_benchmarking_extension.h
@@ -48,7 +48,14 @@ class GpuBenchmarking : public gin::Wrappable<GpuBenchmarking> {
   bool GestureSourceTypeSupported(int gesture_source_type);
   bool SmoothScrollBy(gin::Arguments* args);
   bool SmoothDrag(gin::Arguments* args);
+
+  // This function generates a scroll followed by a fling. The default input
+  // source is touch; Source, velocity_x, and velocity_y are extra args that
+  // are necessary for a touchpad fling. Note that the callback function of
+  // swipe will get called only when the GFS is handled by the compositor
+  // thread (http://crbug.com/704148).
   bool Swipe(gin::Arguments* args);
+
   bool ScrollBounce(gin::Arguments* args);
   bool PinchBy(gin::Arguments* args);
   bool Tap(gin::Arguments* args);