The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/1fd3d2d1eb72daeb2df8d02681320159d19a45b4

commit 1fd3d2d1eb72daeb2df8d02681320159d19a45b4
Author: stanisc <stanisc@chromium.org>
Date: Tue Dec 13 22:51:20 2016

Remove MessagePumpForGpu

MessagePumpForGpu isn't needed anymore because all GPU windows have been
moved off the main thread and the main GPU thread has been switched to
DEFAULT message pump.

BUG= 671394 

Review-Url: https://codereview.chromium.org/2573953002
Cr-Commit-Position: refs/heads/master@{#438319}

[modify] https://crrev.com/1fd3d2d1eb72daeb2df8d02681320159d19a45b4/base/message_loop/message_loop_unittest.cc
[modify] https://crrev.com/1fd3d2d1eb72daeb2df8d02681320159d19a45b4/base/message_loop/message_pump_win.cc
[modify] https://crrev.com/1fd3d2d1eb72daeb2df8d02681320159d19a45b4/base/message_loop/message_pump_win.h