Add enable_media_router defines for GN and gyp.

build/common.gypi

 # 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.
 
 # IMPORTANT:
 # Please don't directly include this file if you are building via gyp_chromium,
 # since gyp_chromium is automatically forcing its inclusion.
 {
   # Variables expected to be overriden on the GYP command line (-D) or by
   # ~/.gyp/include.gypi.
@@ skipping 494 matching lines @@
       #   0: Small tables, lower accuracy
       #   2: Large tables, high accuracy
       'cld2_table_size%': 2,
 
       # Enable spell checker.
       'enable_spellcheck%': 1,
 
       # Webrtc compilation is enabled by default. Set to 0 to disable.
       'enable_webrtc%': 1,
 
+      # Media router support is enabled by default. Set to 0 to disable.
+      'enable_media_router%': 1,      

[DaleCurtis, 2015/02/24 00:24:22]

Do you plan to upstream with this on by default?

[Kevin M, 2015/02/24 01:49:43]

Yes. We'll want it on so that we can benefit from Chromium's continuous
integration and trybots while we upstream.

+
       # Enables use of the session service, which is enabled by default.
       # Support for disabling depends on the platform.
       'enable_session_service%': 1,
 
       # Enables theme support, which is enabled by default.  Support for
       # disabling depends on the platform.
       'enable_themes%': 1,
 
       # Enables autofill dialog and associated features; disabled by default.
       'enable_autofill_dialog%' : 0,
@@ skipping 338 matching lines @@
         # gcc >= 4.8 or clang.
         # http://gcc.gnu.org/wiki/DebugFission
         ['OS=="linux" and target_arch=="x64"', {
           'linux_use_debug_fission%': 1,
         }, {
           'linux_use_debug_fission%': 0,
         }],
 
         ['OS=="android" or OS=="ios"', {
           'enable_captive_portal_detection%': 0,
+          'enable_media_router%': 0,
         }, {
           'enable_captive_portal_detection%': 1,
+          'enable_media_router%': 1,
         }],
 
         # Enable Skia UI text drawing incrementally on different platforms.
         # http://crbug.com/105550
         #
         # On Aura, this allows per-tile painting to be used in the browser
         # compositor.
         ['OS!="android"', {
           'use_canvas_skia%': 1,
         }],
@@ skipping 219 matching lines @@
     'chroot_cmd%': '<(chroot_cmd)',
     'system_libdir%': '<(system_libdir)',
     'component%': '<(component)',
     'win_analyze%': '<(win_analyze)',
     'enable_resource_whitelist_generation%': '<(enable_resource_whitelist_generation)',
     'use_titlecase_in_grd%': '<(use_titlecase_in_grd)',
     'use_third_party_translations%': '<(use_third_party_translations)',
     'remoting%': '<(remoting)',
     'enable_one_click_signin%': '<(enable_one_click_signin)',
     'enable_pre_sync_backup%': '<(enable_pre_sync_backup)',
+    'enable_media_router%': '<(enable_media_router)',
     'enable_webrtc%': '<(enable_webrtc)',
     'chromium_win_pch%': '<(chromium_win_pch)',
     'configuration_policy%': '<(configuration_policy)',
     'safe_browsing%': '<(safe_browsing)',
     'enable_web_speech%': '<(enable_web_speech)',
     'notifications%': '<(notifications)',
     'clang_use_chrome_plugins%': '<(clang_use_chrome_plugins)',
     'mac_want_real_dsym%': '<(mac_want_real_dsym)',
     'asan%': '<(asan)',
     'asan_blacklist%': '<(asan_blacklist)',
@@ skipping 983 matching lines @@
       }],
       ['enable_settings_app==1', {
         'grit_defines': ['-D', 'enable_settings_app'],
       }],
       ['enable_google_now==1', {
         'grit_defines': ['-D', 'enable_google_now'],
       }],
       ['use_concatenated_impulse_responses==1', {
         'grit_defines': ['-D', 'use_concatenated_impulse_responses'],
       }],
+      ['enable_media_router==1', {
+        'grit_defines': ['-D', 'enable_media_router'],
+      }],
       ['enable_webrtc==1', {
         'grit_defines': ['-D', 'enable_webrtc'],
       }],
       ['enable_hangout_services_extension==1', {
         'grit_defines': ['-D', 'enable_hangout_services_extension'],
       }],
       ['enable_task_manager==1', {
         'grit_defines': ['-D', 'enable_task_manager'],
       }],
       ['notifications==1', {
@@ skipping 3795 matching lines @@
     # settings in target dicts.  SYMROOT is a special case, because many other
     # Xcode variables depend on it, including variables such as
     # PROJECT_DERIVED_FILE_DIR.  When a source group corresponding to something
     # like PROJECT_DERIVED_FILE_DIR is added to a project, in order for the
     # files to appear (when present) in the UI as actual files and not red
     # red "missing file" proxies, the correct path to PROJECT_DERIVED_FILE_DIR,
     # and therefore SYMROOT, needs to be set at the project level.
     'SYMROOT': '<(DEPTH)/xcodebuild',
   },
 }