Add gmock into our dependencies.

base/base.gyp

Index: base/base.gyp
diff --git a/base/base.gyp b/base/base.gyp
index 33550428aed6c0cfa542a8fe460d2ed14ce50727..70c0de8814068952a3d7409534e71ca18338b559 100644
--- a/base/base.gyp
+++ b/base/base.gyp
@@ -553,16 +553,13 @@
       'type': 'executable',
       'msvs_guid': '27A30967-4BBA-48D1-8522-CDE95F7B1CEC',
       'sources': [
-        'crypto/signature_verifier_unittest.cc',
-        'gfx/jpeg_codec_unittest.cc',
-        'gfx/native_theme_unittest.cc',
-        'gfx/png_codec_unittest.cc',
-        'gfx/rect_unittest.cc',
         'at_exit_unittest.cc',
         'atomicops_unittest.cc',
         'clipboard_unittest.cc',
         'command_line_unittest.cc',
         'condition_variable_unittest.cc',
+        'crypto/signature_verifier_unittest.cc',
+        'gmock_unittest.cc',
         'data_pack_unittest.cc',
         'debug_util_unittest.cc',
         'directory_watcher_unittest.cc',
@@ -571,6 +568,10 @@
         'file_path_unittest.cc',
         'file_util_unittest.cc',
         'file_version_info_unittest.cc',
+        'gfx/jpeg_codec_unittest.cc',
+        'gfx/native_theme_unittest.cc',
+        'gfx/png_codec_unittest.cc',
+        'gfx/rect_unittest.cc',
         'histogram_unittest.cc',
         'hmac_unittest.cc',
         'idletimer_unittest.cc',
@@ -636,6 +637,7 @@
         'base',
         'base_gfx',
         '../skia/skia.gyp:skia',
+        '../testing/gmock.gyp:gmock',
         '../testing/gtest.gyp:gtest',
       ],
       'conditions': [