Remove the ENABLE_GPU #define and enable_gpu gyp variable

webkit/common/gpu/webgraphicscontext3d_in_process_command_buffer_impl.h

 // Copyright (c) 2012 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 WEBKIT_COMMON_GPU_WEBGRAPHICSCONTEXT3D_IN_PROCESS_COMMAND_BUFFER_IMPL_H_
 #define WEBKIT_COMMON_GPU_WEBGRAPHICSCONTEXT3D_IN_PROCESS_COMMAND_BUFFER_IMPL_H_
 
-#if defined(ENABLE_GPU)
-
 #include <vector>
 
 #include "base/compiler_specific.h"
 #include "base/memory/scoped_ptr.h"
 #include "third_party/WebKit/public/platform/WebGraphicsContext3D.h"
 #include "third_party/WebKit/public/platform/WebString.h"
 #include "ui/gfx/native_widget_types.h"
 #include "webkit/common/gpu/webkit_gpu_export.h"
 
 namespace gpu {
@@ skipping 564 matching lines @@
 
   // Errors raised by synthesizeGLError().
   std::vector<WGC3Denum> synthetic_errors_;
 
   uint32_t flush_id_;
 };
 
 }  // namespace gpu
 }  // namespace webkit
 
-#endif  // defined(ENABLE_GPU)
 #endif  // WEBKIT_COMMON_GPU_WEBGRAPHICSCONTEXT3D_IN_PROCESS_COMMAND_BUFFER_IMPL_H_