Add a unified audio I/O backend for ChromeOS.

media/media.gyp

Index: media/media.gyp
diff --git a/media/media.gyp b/media/media.gyp
index f056ff8b391e638471d8f61b7b2cb0aa97131677..61939c0fe165bd33958370097c1b5a1232d104a5 100644
--- a/media/media.gyp
+++ b/media/media.gyp
@@ -99,8 +99,8 @@
         'audio/cras/audio_manager_cras.h',
         'audio/cras/cras_input.cc',
         'audio/cras/cras_input.h',
-        'audio/cras/cras_output.cc',
-        'audio/cras/cras_output.h',
+        'audio/cras/cras_unified.cc',
+        'audio/cras/cras_unified.h',
         'audio/cross_process_notification.cc',
         'audio/cross_process_notification.h',
         'audio/cross_process_notification_posix.cc',
@@ -627,8 +627,8 @@
                 'audio/cras/audio_manager_cras.h',
                 'audio/cras/cras_input.cc',
                 'audio/cras/cras_input.h',
-                'audio/cras/cras_output.cc',
-                'audio/cras/cras_output.h',
+                'audio/cras/cras_unified.cc',
+                'audio/cras/cras_unified.h',
               ],
             }],
           ],
@@ -639,8 +639,8 @@
             'audio/cras/audio_manager_cras.h',
             'audio/cras/cras_input.cc',
             'audio/cras/cras_input.h',
-            'audio/cras/cras_output.cc',
-            'audio/cras/cras_output.h',
+            'audio/cras/cras_unified.cc',
+            'audio/cras/cras_unified.h',
           ],
         }],
         ['os_posix == 1 and OS != "mac" and OS != "ios" and OS != "android" and chromeos != 1', {
@@ -1007,7 +1007,7 @@
             ['use_cras == 1', {
               'sources': [
                 'audio/cras/cras_input_unittest.cc',
-                'audio/cras/cras_output_unittest.cc',
+                'audio/cras/cras_unified_unittest.cc',
               ],
               'defines': [
                 'USE_CRAS',