gpu: Add async upload functions.

gpu/command_buffer/service/feature_info.cc

Index: gpu/command_buffer/service/feature_info.cc
diff --git a/gpu/command_buffer/service/feature_info.cc b/gpu/command_buffer/service/feature_info.cc
index 3c2365e3dc4075215866ba2ae58479f6abd5338c..e89908113db7d9e52fbcecf6b8aaa7ab30c9b614 100644
--- a/gpu/command_buffer/service/feature_info.cc
+++ b/gpu/command_buffer/service/feature_info.cc
@@ -235,6 +235,7 @@ void FeatureInfo::AddFeatures(const char* desired_features) {
   bool npot_ok = false;
 
   AddExtensionString("GL_ANGLE_translated_shader_source");
+  AddExtensionString("GL_CHROMIUM_async_tasks");

[greggman, 2012/11/29 02:18:18]

Seems like this should maybe be more specific. Like
GL_CHROMIUM_asycn_texture_upload?

What do you think?

[epennerAtGoogle, 2012/11/29 03:47:23]

It was like that before, but I plan to add Async readbacks as well. Although I
could make them separate:
- GL_CHROMIUM_async_texture_upload
- GL_CHROMIUM_async_texture_readbacks.
I have a very weak preference to keep it as just one. Whichever you think is
best.

[reveman, 2012/11/29 04:13:32]

"task" is a bit ambiguous. if use one extension maybe
CHROMIUM_async_pixel_transfer?

also not sure async is a good description. makes it seem like standard texture
uploads are synchronous. maybe CHROMIUM_idle_pixel_transfer or 
CHROMIUM_unsequenced_pixel_transfer is better?

[epennerAtGoogle, 2012/11/29 19:28:43]

I like async-pixel-transfer the most, so I'll use that unless there is another
preference. Similarly I'll use async-pixel-transfers-completed for the query.

   AddExtensionString("GL_CHROMIUM_bind_uniform_location");
   AddExtensionString("GL_CHROMIUM_command_buffer_query");
   AddExtensionString("GL_CHROMIUM_command_buffer_latency_query");