Properly set loopback device ID for system audio capture.

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.
   'variables': {
     # Putting a variables dict inside another variables dict looks kind of
     # weird.  This is done so that 'host_arch', 'chromeos', etc are defined as
     # variables within the outer variables dict here.  This is necessary
     # to get these variables defined for the conditions within this variables
     # dict that operate on these variables.
     'variables': {
       'variables': {
         'variables': {
           'variables': {
             # Whether we're building a ChromeOS build.
             'chromeos%': 0,
 
             # Whether or not we are using the Aura windowing framework.
             'use_aura%': 0,
 
             # Whether or not we are building the Ash shell.
             'use_ash%': 0,
 
+            # Whether or not we are using CRAS, the ChromeOS Audio Server.
+            'use_cras%': 0,
+
             # Use a raw surface abstraction.
             'use_ozone%': 0,
           },
           # Copy conditionally-set variables out one scope.
           'chromeos%': '<(chromeos)',
           'use_aura%': '<(use_aura)',
           'use_ash%': '<(use_ash)',
+          'use_cras%': '<(use_cras)',
           'use_ozone%': '<(use_ozone)',
 
           # Whether we are using Views Toolkit
           'toolkit_views%': 0,
 
           # Use OpenSSL instead of NSS. Under development: see http://crbug.com/62803
           'use_openssl%': 0,
 
           # Disable viewport meta tag by default.
           'enable_viewport%': 0,
@@ skipping 44 matching lines @@
               # gyp.
               'host_arch%':
                 '<!(uname -m | sed -e "s/i.86/ia32/;s/x86_64/x64/;s/amd64/x64/;s/arm.*/arm/;s/i86pc/ia32/")',
             }],
           ],
         },
         # Copy conditionally-set variables out one scope.
         'chromeos%': '<(chromeos)',
         'use_aura%': '<(use_aura)',
         'use_ash%': '<(use_ash)',
+        'use_cras%': '<(use_cras)',
         'use_ozone%': '<(use_ozone)',
         'use_openssl%': '<(use_openssl)',
         'enable_viewport%': '<(enable_viewport)',
         'enable_hidpi%': '<(enable_hidpi)',
         'enable_touch_ui%': '<(enable_touch_ui)',
         'buildtype%': '<(buildtype)',
         'branding%': '<(branding)',
         'host_arch%': '<(host_arch)',
 
         # Default architecture we're building for is the architecture we're
@@ skipping 61 matching lines @@
       },
 
       # Copy conditionally-set variables out one scope.
       'chromeos%': '<(chromeos)',
       'host_arch%': '<(host_arch)',
       'target_arch%': '<(target_arch)',
       'toolkit_views%': '<(toolkit_views)',
       'toolkit_uses_gtk%': '<(toolkit_uses_gtk)',
       'use_aura%': '<(use_aura)',
       'use_ash%': '<(use_ash)',
+      'use_cras%': '<(use_cras)',
       'use_ozone%': '<(use_ozone)',
       'use_openssl%': '<(use_openssl)',
       'enable_viewport%': '<(enable_viewport)',
       'enable_hidpi%': '<(enable_hidpi)',
       'enable_touch_ui%': '<(enable_touch_ui)',
       'android_webview_build%': '<(android_webview_build)',
       'google_tv%': '<(google_tv)',
       'enable_app_list%': '<(enable_app_list)',
       'use_default_render_theme%': '<(use_default_render_theme)',
       'buildtype%': '<(buildtype)',
@@ skipping 556 matching lines @@
 
     # Copy conditionally-set variables out one scope.
     'branding%': '<(branding)',
     'buildtype%': '<(buildtype)',
     'target_arch%': '<(target_arch)',
     'host_arch%': '<(host_arch)',
     'toolkit_views%': '<(toolkit_views)',
     'ui_compositor_image_transport%': '<(ui_compositor_image_transport)',
     'use_aura%': '<(use_aura)',
     'use_ash%': '<(use_ash)',
+    'use_cras%': '<(use_cras)',
     'use_openssl%': '<(use_openssl)',
     'use_nss%': '<(use_nss)',
     'os_bsd%': '<(os_bsd)',
     'os_posix%': '<(os_posix)',
     'use_glib%': '<(use_glib)',
     'use_pango%': '<(use_pango)',
     'use_ozone%': '<(use_ozone)',
     'toolkit_uses_gtk%': '<(toolkit_uses_gtk)',
     'use_x11%': '<(use_x11)',
     'use_gnome_keyring%': '<(use_gnome_keyring)',
@@ skipping 1153 matching lines @@
       }],
       ['ui_compositor_image_transport==1', {
         'defines': ['UI_COMPOSITOR_IMAGE_TRANSPORT'],
       }],
       ['use_aura==1', {
         'defines': ['USE_AURA=1'],
       }],
       ['use_ash==1', {
         'defines': ['USE_ASH=1'],
       }],
+      ['use_cras==1', {
+        'defines': ['USE_CRAS=1'],
+      }],
       ['use_ozone==1', {
         'defines': ['USE_OZONE=1'],
       }],
       ['use_default_render_theme==1', {
         'defines': ['USE_DEFAULT_RENDER_THEME=1'],
       }],
       ['use_libjpeg_turbo==1', {
         'defines': ['USE_LIBJPEG_TURBO=1'],
       }],
       ['use_nss==1', {
@@ skipping 2746 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',
   },
 }