gpu: Add YCbCr 420v extension.

On Mac we currently support textures backed by GpuMemoryBuffer
with UYVY_422 format when GL_APPLE_ycbcr_422 is available.
This allows both to use the backing IOSurface as CALayers and to
bind the IOSurface to a GL texture for sampling.

420v IOSurfaces, while being more efficient when used as a CALayer,
don't support being sampled from GL.

This CL adds a CHROMIUM extension, that when available, allows users
of CHROMIUM command buffer to use a 420v IOSurface from GL as an RGB
texture.

This is achieved converting the IOSurface from YUV to RGB when it's
bound to a texture on the service side.

This will allow to use 420v for video playback using VideoLayerImpl
(promoted to CALayer) and from SkCanvasVideoRenderer when needed (WebGL,
Canvas & co.)

BUG=524582

Review URL: https://codereview.chromium.org/1419733005

Cr-Commit-Position: refs/heads/master@{#363148}

1 files changed, 1 insertions, 0 deletions

diff --git a/gpu/command_buffer/build_gles2_cmd_buffer.py b/gpu/command_buffer/build_gles2_cmd_buffer.py
index 6b672b2..eb5724a 100755
--- a/gpu/command_buffer/build_gles2_cmd_buffer.py
+++ b/gpu/command_buffer/build_gles2_cmd_buffer.py
@@ -1949,6 +1949,7 @@ _NAMED_TYPE_INFO = {
       'GL_RGB',
       'GL_RGB_YUV_420_CHROMIUM',
       'GL_RGB_YCBCR_422_CHROMIUM',
+      'GL_RGB_YCBCR_420V_CHROMIUM',
       'GL_RGBA',
     ],
   },