Add half-float IOSurface GpuMemoryBuffer support
Add support for gpu rasterization to half-float RGBA textures.
Do not add software rasterization support for half-float RGBA textures.
While this is possible, software rasterization to half-float is not a good
idea for performance reasons.
BUG=655171
CQ_INCLUDE_TRYBOTS=master.tryserver.blink:linux_trusty_blink_rel;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
Review-Url: https://codereview.chromium.org/2786103003
Cr-Commit-Position: refs/heads/master@{#464114}
24 files changed
