Adds the UserInputMonitor implementation for Mac.

media/media.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,
     # Override to dynamically link the cras (ChromeOS audio) library.
     'use_cras%': 0,
     # Option e.g. for Linux distributions to link pulseaudio directly
@@ skipping 289 matching lines @@
         'base/sinc_resampler.cc',
         'base/sinc_resampler.h',
         'base/stream_parser.cc',
         'base/stream_parser.h',
         'base/stream_parser_buffer.cc',
         'base/stream_parser_buffer.h',
         'base/text_track.h',
         'base/user_input_monitor.cc',
         'base/user_input_monitor.h',
         'base/user_input_monitor_linux.cc',
-        'base/user_input_monitor_mac.mm',
+        'base/user_input_monitor_mac.cc',
         'base/user_input_monitor_win.cc',
         'base/video_decoder.cc',
         'base/video_decoder.h',
         'base/video_decoder_config.cc',
         'base/video_decoder_config.h',
         'base/video_frame.cc',
         'base/video_frame.h',
         'base/video_renderer.cc',
         'base/video_renderer.h',
         'base/video_util.cc',
@@ skipping 1355 matching lines @@
           'sources': [
             'tools/media_bench/media_bench.cc',
           ],
           # TODO(jschuh): crbug.com/167187 fix size_t to int truncations.
           'msvs_disabled_warnings': [ 4267, ],
         },
       ],
     }],
   ],
 }