No need to link base-unittests with GMock.

test/base-unittests/base-unittests.gyp

 # Copyright 2014 the V8 project 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': {
     'v8_code': 1,
   },
   'includes': ['../../build/toolchain.gypi', '../../build/features.gypi'],
   'targets': [
     {
       'target_name': 'base-unittests',
       'type': 'executable',
       'dependencies': [
-        '../../testing/gmock.gyp:gmock_main',
         '../../testing/gtest.gyp:gtest',
+        '../../testing/gtest.gyp:gtest_main',
         '../../tools/gyp/v8.gyp:v8_libbase',
       ],
       'include_dirs': [
         '../..',
       ],
       'sources': [  ### gcmole(all) ###
         'cpu-unittest.cc',
         'platform/condition-variable-unittest.cc',
         'platform/mutex-unittest.cc',
         'platform/platform-unittest.cc',
         'platform/time-unittest.cc',
         'utils/random-number-generator-unittest.cc',
       ],
     },
   ],
 }