Remove the ENABLE_GPU #define and enable_gpu gyp variable

content/content_renderer.gypi

 # 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.
 
 {
   'dependencies': [
     '../jingle/jingle.gyp:jingle_glue',
     '../media/media.gyp:media',
     '../net/net.gyp:net',
     '../skia/skia.gyp:skia',
@@ skipping 678 matching lines @@
         'renderer/render_widget_fullscreen_pepper.cc',
         'renderer/render_widget_fullscreen_pepper.h',
       ],
     }],
     ['enable_pepper_cdms != 1', {
       'sources!': [
         'renderer/media/crypto/ppapi_decryptor.cc',
         'renderer/media/crypto/ppapi_decryptor.h',
       ],
     }],
-    ['enable_gpu!=1', {
-      'sources!': [
-        'renderer/pepper/ppb_graphics_3d_impl.cc',
-        'renderer/pepper/ppb_graphics_3d_impl.h',
-        'renderer/pepper/ppb_open_gl_es_impl.cc',
-      ],
-    }],
     ['use_openssl==1', {
       'sources!': [
         'renderer/webcrypto/webcrypto_impl_nss.cc',
       ],
       'dependencies': [
         '../third_party/openssl/openssl.gyp:openssl',
       ],
     }, {
       'sources!': [
         'renderer/webcrypto/webcrypto_impl_openssl.cc',
@@ skipping 13 matching lines @@
     }],
   ],
   'target_conditions': [
     ['OS=="android"', {
       'sources/': [
         ['include', '^renderer/render_view_linux\\.cc$'],
       ],
     }],
   ],
 }