Add media router common classes and unittests.

chrome/chrome_browser.gypi

 # Copyright 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': {
     # All .cc, .h, .m, and .mm files under browser except for:
     # * tests and mocks.
     # * code below browser/chromeos
     # * code below browser/extensions
@@ skipping 3166 matching lines @@
             ['use_aura==0 or OS=="win"', {
               'sources!': [
                 'browser/background/background_mode_manager_aura.cc',
               ],
             }],
           ],
         }],
         ['enable_task_manager==1', {
           'sources': [ '<@(chrome_browser_task_manager_sources)' ],
         }],
+        ['enable_media_router==1', {
+          'dependencies': [
+            'browser/media/router/media_router.gyp:media_router',
+          ],
+        }],
         ['enable_spellcheck==1', {
           'sources': [ '<@(chrome_browser_spellchecker_sources)' ],
           'dependencies': [
             '../third_party/hunspell/hunspell.gyp:hunspell',
           ],
         }],
         ['disable_nacl==0', {
           'sources': [ '<@(chrome_browser_nacl_sources)' ],
           'dependencies': [
             '../components/nacl.gyp:nacl_browser',
@@ skipping 550 matching lines @@
           'variables': {
             'proto_in_dir': 'browser/sync_file_system/drive_backend',
             'proto_out_dir': 'chrome/browser/sync_file_system/drive_backend',
           },
           'includes': [ '../build/protoc.gypi' ]
         },
       ],
     },],
   ],
 }