Aura does not need to depend on gpu target.

ui/aura/aura.gyp

 # 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.
 
 {
   'variables': {
     'chromium_code': 1,
   },
   'targets': [
     {
       'target_name': 'aura',
       'type': '<(component)',
       'dependencies': [
         '../../base/base.gyp:base',
         '../../base/base.gyp:base_i18n',
         '../../base/third_party/dynamic_annotations/dynamic_annotations.gyp:dynamic_annotations',
-        '../../gpu/gpu.gyp:gpu',
         '../../skia/skia.gyp:skia',
         '../base/ui_base.gyp:ui_base',
         '../compositor/compositor.gyp:compositor',
         '../events/events.gyp:events',
         '../events/events.gyp:events_base',
         '../events/platform/events_platform.gyp:events_platform',
         '../gfx/gfx.gyp:gfx',
         '../gfx/gfx.gyp:gfx_geometry',
       ],
       'defines': [
@@ skipping 27 matching lines @@
         'client/window_tree_client.h',
         'env.cc',
         'env.h',
         'env_observer.h',
         'input_state_lookup.cc',
         'input_state_lookup.h',
         'input_state_lookup_win.cc',
         'input_state_lookup_win.h',
         'layout_manager.cc',
         'layout_manager.h',
-        'remote_window_tree_host_win.cc',       
+        'remote_window_tree_host_win.cc',
         'remote_window_tree_host_win.h',
         'scoped_window_targeter.cc',
         'scoped_window_targeter.h',
         'window.cc',
         'window.h',
         'window_event_dispatcher.cc',
         'window_event_dispatcher.h',
         'window_delegate.h',
         'window_layer_type.h',
         'window_observer.h',
@@ skipping 143 matching lines @@
         }],
       ]
     },
     {
       'target_name': 'aura_bench',
       'type': 'executable',
       'dependencies': [
         '../../base/base.gyp:base',
         '../../base/base.gyp:base_i18n',
         '../../cc/cc.gyp:cc',
+        '../../gpu/gpu.gyp:gles2_implementation',
         '../../skia/skia.gyp:skia',
         '../../third_party/icu/icu.gyp:icui18n',
         '../../third_party/icu/icu.gyp:icuuc',
         '../base/ui_base.gyp:ui_base',
         '../compositor/compositor.gyp:compositor',
         '../compositor/compositor.gyp:compositor_test_support',
         '../events/events.gyp:events',
         '../gfx/gfx.gyp:gfx',
         '../gfx/gfx.gyp:gfx_geometry',
         'aura',
@@ skipping 53 matching lines @@
         ['OS=="linux" and use_allocator!="none"', {
           'dependencies': [
            # See http://crbug.com/162998#c4 for why this is needed.
             '../../base/allocator/allocator.gyp:allocator',
           ],
         }],
       ],
     },
   ],
 }