Sahel, feel free to make this as duplicate if there is another one tracking this or add further details here. Thanks.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/8fdb30474d136a362f8896e938bc0254ce93b725

commit 8fdb30474d136a362f8896e938bc0254ce93b725
Author: Lan Wei <lanwei@chromium.org>
Date: Sat Aug 18 01:03:40 2018

Add touchpad swipe action to GpuBenchmarking

For testing purpose, we want to add a new action to GpuBenchmarking to
simulate the touchpad swipe action, which is a mouse wheel scrolling
and a fling.

Now the GestureSourceType of MOUSE_INPUT and TOUCHPAD_INPUT are treated
the same, but I will have another CL to separate them.

Bug:  864001 
Change-Id: I736831d50e1d0adf945ae22b6b045a12ee0ae95c
Reviewed-on: https://chromium-review.googlesource.com/1161184
Reviewed-by: Timothy Dresser <tdresser@chromium.org>
Reviewed-by: Nasko Oskov <nasko@chromium.org>
Reviewed-by: Dirk Pranke <dpranke@chromium.org>
Reviewed-by: Sahel Sharify <sahel@chromium.org>
Reviewed-by: Navid Zolghadr <nzolghadr@chromium.org>
Commit-Queue: Lan Wei <lanwei@chromium.org>
Cr-Commit-Position: refs/heads/master@{#584272}
[modify] https://crrev.com/8fdb30474d136a362f8896e938bc0254ce93b725/content/browser/renderer_host/input/synthetic_gesture_controller_unittest.cc
[modify] https://crrev.com/8fdb30474d136a362f8896e938bc0254ce93b725/content/browser/renderer_host/input/synthetic_gesture_target_aura.cc
[modify] https://crrev.com/8fdb30474d136a362f8896e938bc0254ce93b725/content/browser/renderer_host/input/synthetic_gesture_target_base.cc
[modify] https://crrev.com/8fdb30474d136a362f8896e938bc0254ce93b725/content/browser/renderer_host/input/synthetic_smooth_move_gesture.cc
[modify] https://crrev.com/8fdb30474d136a362f8896e938bc0254ce93b725/content/browser/renderer_host/input/synthetic_smooth_move_gesture.h
[modify] https://crrev.com/8fdb30474d136a362f8896e938bc0254ce93b725/content/browser/renderer_host/input/synthetic_smooth_scroll_gesture.cc
[modify] https://crrev.com/8fdb30474d136a362f8896e938bc0254ce93b725/content/common/input/synthetic_gesture_params.h
[modify] https://crrev.com/8fdb30474d136a362f8896e938bc0254ce93b725/content/common/input/synthetic_smooth_scroll_gesture_params.cc
[modify] https://crrev.com/8fdb30474d136a362f8896e938bc0254ce93b725/content/common/input/synthetic_smooth_scroll_gesture_params.h
[modify] https://crrev.com/8fdb30474d136a362f8896e938bc0254ce93b725/content/common/input_messages.h
[modify] https://crrev.com/8fdb30474d136a362f8896e938bc0254ce93b725/content/renderer/gpu/gpu_benchmarking_extension.cc
[modify] https://crrev.com/8fdb30474d136a362f8896e938bc0254ce93b725/third_party/WebKit/LayoutTests/TestExpectations
[copy] https://crrev.com/8fdb30474d136a362f8896e938bc0254ce93b725/third_party/WebKit/LayoutTests/fast/events/touch/gesture/gesture-scrollbar-touchpad-fling.html
[rename] https://crrev.com/8fdb30474d136a362f8896e938bc0254ce93b725/third_party/WebKit/LayoutTests/fast/events/touch/gesture/gesture-scrollbar-touchscreen-fling.html
[modify] https://crrev.com/8fdb30474d136a362f8896e938bc0254ce93b725/third_party/WebKit/LayoutTests/resources/gesture-util.js
[modify] https://crrev.com/8fdb30474d136a362f8896e938bc0254ce93b725/third_party/blink/public/platform/web_input_event.h