gpu: Add CHROMIUM_copy_image extension.

cc/test/test_gles2_interface.h

Index: cc/test/test_gles2_interface.h
diff --git a/cc/test/test_gles2_interface.h b/cc/test/test_gles2_interface.h
index ec969fb92dbf87b876ca87fa0a2bf0b5dee282cb..500b372b8dc0bac285e4304e04a556e6904f50e7 100644
--- a/cc/test/test_gles2_interface.h
+++ b/cc/test/test_gles2_interface.h
@@ -113,6 +113,16 @@ class TestGLES2Interface : public gpu::gles2::GLES2InterfaceStub {
                               GLint image_id,
                               GLint fence_id) override;
   void ReleaseTexImage2DCHROMIUM(GLenum target, GLint image_id) override;
+  void CopyImageSubDataCHROMIUM(GLint source_image_id,
+                                GLint dest_texture_id,
+                                GLint xoffset,
+                                GLint yoffset,
+                                GLint x,
+                                GLint y,
+                                GLsizei width,
+                                GLsizei height,
+                                GLint in_fence_id,
+                                GLint out_fence_id) override;
   void FramebufferRenderbuffer(GLenum target,
                                GLenum attachment,
                                GLenum renderbuffertarget,