GitLab

This refactor CL allows useful GPU service flags like
--enable-gpu-service-logging (log all GL commands processed) and
--enable-gpu-debugging (check for GL error after every command) to be
used when running unittests (e.g. cc_unittests) that use
InProcessCommandBuffer.

There are no security implications of this change because

- only tests use the codepath updated here (Viz and android webview do
  not)

- flags are whitelist passed to child processes (renderer/GPU processes)

ParseGpuPreferences could not easily be added as a member of
GpuPreferences because of dependencies.

  - ParseGpuPreferences depends on gpu/command_buffer/service:gles2 to
    check if passthrough decoder is enabled.

  - gpu/command_buffer/service:gles2 has a dependency on
    gpu/command_buffer/service:service

  - GpuPreferences lives in gpu/command_buffer/service:service

  - Moving GpuPreferences to gpu/command_buffer/service:gles2 seems
    non-trivial. I did not want to introduce a new component just for
    GpuPreferences.

ParseGpuPreferences did not seem to belong to gpu_preferences_util.h
because that is IPC specific.

Cq-Include-Trybots: luci.chromium.try:android_optional_gpu_tests_rel;luci.chromium.try:linux_optional_gpu_tests_rel;luci.chromium.try:mac_optional_gpu_tests_rel;luci.chromium.try:win_optional_gpu_tests_rel
Change-Id: I76db4fe0eebd3eb7720fa24265f69093715c6137
Reviewed-on: https://chromium-review.googlesource.com/1019662Reviewed-by: Antoine Labour <piman@chromium.org>
Commit-Queue: Jonathan Backer <backer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#553707}