Add some unit tests for mojo's Buffer classes.

mojo/mojo.gyp

 # Copyright 2013 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': [
     {
@@ skipping 108 matching lines @@
       'dependencies': [
         '../testing/gtest.gyp:gtest',
         'mojo_bindings',
         'mojo_public_test_support',
         'mojo_run_all_unittests',
         'mojo_system',
       ],
       'sources': [
         'public/tests/bindings_connector_unittest.cc',
         'public/tests/bindings_remote_ptr_unittest.cc',
+        'public/tests/buffer_unittest.cc',
         'public/tests/math_calculator.mojom',
         'public/tests/system_core_unittest.cc',
       ],
       'includes': [ 'public/bindings/mojom_bindings_generator.gypi' ],
     },
     {
       'target_name': 'mojo_public_perftests',
       'type': 'executable',
       'dependencies': [
         '../base/base.gyp:base',
@@ skipping 429 matching lines @@
             'java_in_dir': '<(DEPTH)/mojo/shell/android/apk',
             'resource_dir': '<(DEPTH)/mojo/shell/android/apk/res',
             'native_lib_target': 'libmojo_shell',
           },
           'includes': [ '../build/java_apk.gypi' ],
         }
       ],
     }],
   ],
 }