gpu: Use a local int to generate the gmb id.

content/common/generic_shared_memory_id_generator.h

Index: content/common/generic_shared_memory_id_generator.h
diff --git a/content/common/generic_shared_memory_id_generator.h b/content/common/generic_shared_memory_id_generator.h
deleted file mode 100644
index 4640cc1cb07e3750d7e57107c69827b3a62fd9cd..0000000000000000000000000000000000000000
--- a/content/common/generic_shared_memory_id_generator.h
+++ /dev/null
@@ -1,19 +0,0 @@
-// Copyright 2015 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.
-
-#ifndef CONTENT_COMMON_GENERIC_SHARED_MEMORY_ID_GENERATOR_H_
-#define CONTENT_COMMON_GENERIC_SHARED_MEMORY_ID_GENERATOR_H_
-
-#include "ui/gfx/generic_shared_memory_id.h"
-#include "content/common/content_export.h"
-
-namespace content {
-
-// Returns the next GenericSharedMemoryId for the current process. This should
-// be used anywhere a new GenericSharedMemoryId is needed.
-CONTENT_EXPORT gfx::GenericSharedMemoryId GetNextGenericSharedMemoryId();
-
-}  // namespace content
-
-#endif  // CONTENT_COMMON_GENERIC_SHARED_MEMORY_ID_GENERATOR_H_