Expose GLES2Interface to cc

cc/output/context_provider.h

Index: cc/output/context_provider.h
diff --git a/cc/output/context_provider.h b/cc/output/context_provider.h
index a996b2a5d3c3934b6445eb9afd309f314f371e97..f9c28f9f5f200b3ff6442209f65ee3a0ece9b80a 100644
--- a/cc/output/context_provider.h
+++ b/cc/output/context_provider.h
@@ -11,7 +11,10 @@
 
 class GrContext;
 namespace blink { class WebGraphicsContext3D; }
-namespace gpu { class ContextSupport; }
+namespace gpu {
+class ContextSupport;
+namespace gles2 { class GLES2Interface; }
+}
 
 namespace cc {
 struct ManagedMemoryPolicy;
@@ -25,6 +28,7 @@ class ContextProvider : public base::RefCountedThreadSafe<ContextProvider> {
   virtual bool BindToCurrentThread() = 0;
 
   virtual blink::WebGraphicsContext3D* Context3d() = 0;
+  virtual gpu::gles2::GLES2Interface* ContextGL() = 0;
   virtual gpu::ContextSupport* ContextSupport() = 0;
   virtual class GrContext* GrContext() = 0;