gpu: Add CopyTexImage function to GLImage API.

gpu/command_buffer/service/texture_definition.cc

Index: gpu/command_buffer/service/texture_definition.cc
diff --git a/gpu/command_buffer/service/texture_definition.cc b/gpu/command_buffer/service/texture_definition.cc
index 377675cf90d9b80239659e435bc238fa2ef2752d..5928bd2fc15c55d255350ca78b591e621f6869e1 100644
--- a/gpu/command_buffer/service/texture_definition.cc
+++ b/gpu/command_buffer/service/texture_definition.cc
@@ -34,6 +34,7 @@ class GLImageSync : public gfx::GLImage {
   virtual gfx::Size GetSize() OVERRIDE;
   virtual bool BindTexImage(unsigned target) OVERRIDE;
   virtual void ReleaseTexImage(unsigned target) OVERRIDE;
+  virtual bool CopyTexImage(unsigned target) OVERRIDE;
   virtual void WillUseTexImage() OVERRIDE;
   virtual void WillModifyTexImage() OVERRIDE;
   virtual void DidModifyTexImage() OVERRIDE;
@@ -83,6 +84,11 @@ void GLImageSync::ReleaseTexImage(unsigned target) {
   NOTREACHED();
 }
 
+bool GLImageSync::CopyTexImage(unsigned target) {
+  NOTREACHED();
+  return false;
+}
+
 void GLImageSync::WillUseTexImage() {
   if (buffer_.get())
     buffer_->WillRead(this);