Connect up --disable-gl-multisampling to command buffer

gpu/command_buffer/service/context_group.h

Index: gpu/command_buffer/service/context_group.h
diff --git a/gpu/command_buffer/service/context_group.h b/gpu/command_buffer/service/context_group.h
index f3ae4b7c15162827d9c2975f480c5b0c968cc562..80b2e46511b0e365f74aee946e73f9dd54468573 100644
--- a/gpu/command_buffer/service/context_group.h
+++ b/gpu/command_buffer/service/context_group.h
@@ -27,6 +27,7 @@ class RenderbufferManager;
 class ProgramManager;
 class ShaderManager;
 class TextureManager;
+struct DisallowedExtensions;
 
 // A Context Group helps manage multiple GLES2Decoders that share
 // resources.
@@ -38,7 +39,8 @@ class ContextGroup : public base::RefCounted<ContextGroup> {
   ~ContextGroup();
 
   // This should only be called by GLES2Decoder.
-  bool Initialize(const char* allowed_features);
+  bool Initialize(const DisallowedExtensions& disallowed_extensions,
+                  const char* allowed_features);
 
   // Sets the ContextGroup has having a lost context.
   void set_have_context(bool have_context) {