Avoid planar YUV resources when one component EGL images are not supported

gpu/command_buffer/service/gles2_cmd_decoder.cc

Index: gpu/command_buffer/service/gles2_cmd_decoder.cc
diff --git a/gpu/command_buffer/service/gles2_cmd_decoder.cc b/gpu/command_buffer/service/gles2_cmd_decoder.cc
index 68b894846bb0ff89ffbdd837869f1f4f0492aaf6..68bc91b9151b93de0a5f137123f83ed42ca86482 100644
--- a/gpu/command_buffer/service/gles2_cmd_decoder.cc
+++ b/gpu/command_buffer/service/gles2_cmd_decoder.cc
@@ -3593,6 +3593,9 @@ Capabilities GLES2DecoderImpl::GetCapabilities() {
       feature_info_->feature_flags().oes_compressed_etc1_rgb8_texture;
   caps.texture_format_etc1_npot =
       caps.texture_format_etc1 && !workarounds().etc1_power_of_two_only;
+  caps.force_software_yuv_conversion =

[no sievers, 2016/08/24 22:39:18]

nit: Instead of 'force_software_yuv_conversion' maybe we can come up with a
better name that doesn't imply a prescription with knowledge about the client
pipeline, but rather is a simple feature (or feature broken) flag that says
something about the driver capabilities.

How about saying that 'shared (as in across contexts with a mailbox) one
component textures' cannot be used?

[Tobias Sargeant, 2016/08/26 15:52:11]

Done.

+      mailbox_manager()->UsesSync() &&

[no sievers, 2016/08/24 22:39:18]

nit: can you put a comment to explain why we only need to do it for
'UsesSync()'?

[Tobias Sargeant, 2016/08/26 15:52:11]

Done.

+      workarounds().avoid_one_component_egl_images;
   caps.texture_rectangle = feature_info_->feature_flags().arb_texture_rectangle;
   caps.texture_usage = feature_info_->feature_flags().angle_texture_usage;
   caps.texture_storage = feature_info_->feature_flags().ext_texture_storage;