Clean up of GLES2 Command Decoder by moving some of the error state into a separate class.

gpu/command_buffer/service/error_state_mock.cc

Index: gpu/command_buffer/service/error_state_mock.cc
diff --git a/gpu/command_buffer/service/error_state_mock.cc b/gpu/command_buffer/service/error_state_mock.cc
new file mode 100644
index 0000000000000000000000000000000000000000..2a4e709362578ddbb97ed612b0947eeb933fbbd9
--- /dev/null
+++ b/gpu/command_buffer/service/error_state_mock.cc
@@ -0,0 +1,16 @@
+// Copyright (c) 2013 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "gpu/command_buffer/service/error_state_mock.h"
+
+namespace gpu {
+namespace gles2 {
+
+MockErrorState::MockErrorState()
+    : ErrorState() {}
+
+MockErrorState::~MockErrorState() {}
+
+}  // namespace gles2
+}  // namespace gpu