Move GpuClientImpl to //components/viz/host/

GpuClientImpl is moved from //content/browser/gpu/ into
//components/viz/host/ and renamed to GpuClient.

BUG=851488

Cq-Include-Trybots: luci.chromium.try:android_optional_gpu_tests_rel
Change-Id: I27c1586bc269d7e6b7e55f1de16451e1c3528285
Reviewed-on: https://chromium-review.googlesource.com/1171665
Commit-Queue: Mohsen Izadi <[email protected]>
Reviewed-by: Antoine Labour <[email protected]>
Reviewed-by: Scott Violet <[email protected]>
Cr-Commit-Position: refs/heads/master@{#584533}
17 files changed