WebGL: tex(Sub)Image(2D|3D) texImageSource support for RGB10_A2 textures.

gpu/command_buffer/service/gles2_cmd_copy_texture_chromium.cc

Index: gpu/command_buffer/service/gles2_cmd_copy_texture_chromium.cc
diff --git a/gpu/command_buffer/service/gles2_cmd_copy_texture_chromium.cc b/gpu/command_buffer/service/gles2_cmd_copy_texture_chromium.cc
index c9e6bdbc538da2e221549b4c157bb9d48a2fb88b..9a6f883d5ca030d442fade36b219fbbda42f6a7f 100644
--- a/gpu/command_buffer/service/gles2_cmd_copy_texture_chromium.cc
+++ b/gpu/command_buffer/service/gles2_cmd_copy_texture_chromium.cc
@@ -74,6 +74,7 @@ enum {
   D_FORMAT_RGBA16F,
   D_FORMAT_RGBA32F,
   D_FORMAT_R11F_G11F_B10F,
+  D_FORMAT_RGB10_A2,
   NUM_D_FORMAT
 };
 
@@ -269,6 +270,9 @@ ShaderId GetFragmentShaderId(bool premultiply_alpha,
     case GL_R11F_G11F_B10F:
       destFormatIndex = D_FORMAT_R11F_G11F_B10F;
       break;
+    case GL_RGB10_A2:
+      destFormatIndex = D_FORMAT_RGB10_A2;
+      break;
     default:
       NOTREACHED();
       break;