The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/df80093e57efc213bc823f88697af71326a7f4be

commit df80093e57efc213bc823f88697af71326a7f4be
Author: Eric Karl <ericrk@chromium.org>
Date: Thu Oct 26 19:10:34 2017

Update GPU memory pressure handling + add discardable support

Moves program cache specific memory pressure handling from
GpuChannelManager to ProgramCache and adds handling logic for
the ServiceDiscardableManager. Also adds tests to ensure these
classes are working as expected.

Bug:  776034 
Cq-Include-Trybots: master.tryserver.chromium.android:android_optional_gpu_tests_rel;master.tryserver.chromium.linux:linux_optional_gpu_tests_rel;master.tryserver.chromium.mac:mac_optional_gpu_tests_rel;master.tryserver.chromium.win:win_optional_gpu_tests_rel
Change-Id: I12d839e79e969764cd74fd8a328ff1180e41f143
Reviewed-on: https://chromium-review.googlesource.com/654378
Commit-Queue: Eric Karl <ericrk@chromium.org>
Reviewed-by: Antoine Labour <piman@chromium.org>
Cr-Commit-Position: refs/heads/master@{#511912}
[modify] https://crrev.com/df80093e57efc213bc823f88697af71326a7f4be/gpu/command_buffer/service/memory_program_cache.cc
[modify] https://crrev.com/df80093e57efc213bc823f88697af71326a7f4be/gpu/command_buffer/service/memory_program_cache.h
[modify] https://crrev.com/df80093e57efc213bc823f88697af71326a7f4be/gpu/command_buffer/service/memory_program_cache_unittest.cc
[modify] https://crrev.com/df80093e57efc213bc823f88697af71326a7f4be/gpu/command_buffer/service/mocks.cc
[modify] https://crrev.com/df80093e57efc213bc823f88697af71326a7f4be/gpu/command_buffer/service/passthrough_program_cache.cc
[modify] https://crrev.com/df80093e57efc213bc823f88697af71326a7f4be/gpu/command_buffer/service/program_cache.cc
[modify] https://crrev.com/df80093e57efc213bc823f88697af71326a7f4be/gpu/command_buffer/service/program_cache.h
[modify] https://crrev.com/df80093e57efc213bc823f88697af71326a7f4be/gpu/command_buffer/service/program_cache_unittest.cc
[modify] https://crrev.com/df80093e57efc213bc823f88697af71326a7f4be/gpu/command_buffer/service/service_discardable_manager.cc
[modify] https://crrev.com/df80093e57efc213bc823f88697af71326a7f4be/gpu/command_buffer/service/service_discardable_manager.h
[modify] https://crrev.com/df80093e57efc213bc823f88697af71326a7f4be/gpu/command_buffer/service/service_discardable_manager_unittest.cc
[modify] https://crrev.com/df80093e57efc213bc823f88697af71326a7f4be/gpu/ipc/service/gpu_channel_manager.cc