Support audio output device enumeration and selection in PPAPI

ppapi/cpp/BUILD.gn

 # Copyright 2015 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.
 
 if (is_nacl) {
   import("//build/config/nacl/config.gni")
 }
 
 if (is_nacl && is_nacl_glibc) {
   cpp_target_type = "shared_library"
@@ skipping 143 matching lines @@
     "view.cc",
     "view.h",
     "vpn_provider.cc",
     "vpn_provider.h",
     "websocket.cc",
     "websocket.h",
 
     # Dev interfaces.
     "dev/audio_input_dev.cc",
     "dev/audio_input_dev.h",
+    "dev/audio_output_dev.cc",
+    "dev/audio_output_dev.h",
     "dev/buffer_dev.cc",
     "dev/buffer_dev.h",
     "dev/crypto_dev.cc",
     "dev/crypto_dev.h",
     "dev/cursor_control_dev.cc",
     "dev/cursor_control_dev.h",
     "dev/device_ref_dev.cc",
     "dev/device_ref_dev.h",
     "dev/file_chooser_dev.cc",
     "dev/file_chooser_dev.h",
@@ skipping 124 matching lines @@
       # When using gcc, we hide all symbols by default, but that breaks at
       # link time as the test executable requires symbols defined in the
       # shared library.
       configs -= [ "//build/config/gcc:symbol_visibility_hidden" ]
       configs += [ "//build/config/gcc:symbol_visibility_default" ]
 
       cflags = [ "-fPIC" ]
     }
   }
 }