cc/gpu: Add URLs for worker contexts in GPU crash reports.

Plumb through the URL used with a worker context to the GPU
so it can be used to currently report the URL for the current page.
This change only adds support for work sent from raster tasks and
when raster decoder is enabled.

R=piman@chromium.org

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;master.tryserver.blink:linux_trusty_blink_rel
Change-Id: Ib5b20c0cc54df3ecbfb1ef3e13a14f0fcc65e3cb
Reviewed-on: https://chromium-review.googlesource.com/1145685
Commit-Queue: Khushal <khushalsagar@chromium.org>
Reviewed-by: Antoine Labour <piman@chromium.org>
Cr-Commit-Position: refs/heads/master@{#577773}
33 files changed