Free fewer resources when idle in oop raster

freeGpuResources evicts harder to regenerate Skia caches, so use the
slightly lighter weight purgeUnlockedResources when idle for oop raster.
This matches the behavior of gpu raster (see: ContextCacheController).

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: Ia954629b13f8d5fcb50cbd314976e8558b1609d4
Reviewed-on: https://chromium-review.googlesource.com/1141102
Reviewed-by: Eric Karl <ericrk@chromium.org>
Reviewed-by: Khushal <khushalsagar@chromium.org>
Commit-Queue: enne <enne@chromium.org>
Cr-Commit-Position: refs/heads/master@{#576180}
1 file changed