Add texture swizzle back to command buffer.

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 77000c5037eee2a85806b6bb6250b366d81f2f26..3a34afa97a67c3747128f02da7d7ca0f3a853325 100644
--- a/gpu/command_buffer/service/feature_info.cc
+++ b/gpu/command_buffer/service/feature_info.cc
@@ -1491,6 +1491,13 @@ void FeatureInfo::EnableES3Validators() {
     validators_.texture_sized_texture_filterable_internal_format.AddValue(
         GL_BGRA8_EXT);
   }
+
+  if (!IsWebGLContext()) {
+    validators_.texture_parameter.AddValue(GL_TEXTURE_SWIZZLE_R);
+    validators_.texture_parameter.AddValue(GL_TEXTURE_SWIZZLE_G);
+    validators_.texture_parameter.AddValue(GL_TEXTURE_SWIZZLE_B);
+    validators_.texture_parameter.AddValue(GL_TEXTURE_SWIZZLE_A);

[Ken Russell (switch to Gerrit), 2016/12/01 22:46:27]

What about an understanding of the valid values for these parameters?

[Zhenyao Mo, 2016/12/01 22:47:51]

It's already in place. I'll add a test for that.

+  }
 }
 
 bool FeatureInfo::IsWebGLContext() const {