Support audio output device enumeration and selection in PPAPI

ppapi/c/BUILD.gn

Index: ppapi/c/BUILD.gn
diff --git a/ppapi/c/BUILD.gn b/ppapi/c/BUILD.gn
index cd9cf210bd09ec74d7ef1c4c06192c81c782be8a..60fc37abda8c77732ef2ceef14cda8f7ef5270bf 100644
--- a/ppapi/c/BUILD.gn
+++ b/ppapi/c/BUILD.gn
@@ -80,20 +80,30 @@ source_set("c") {
     # Dev interfaces.
     "dev/pp_cursor_type_dev.h",
     "dev/pp_video_dev.h",
+    "dev/ppb_audio_input_dev.h",
+    "dev/ppb_audio_output_dev.h",
     "dev/ppb_buffer_dev.h",
     "dev/ppb_char_set_dev.h",
+    "dev/ppb_crypto_dev.h",
     "dev/ppb_cursor_control_dev.h",
     "dev/ppb_device_ref_dev.h",
     "dev/ppb_file_chooser_dev.h",
+    "dev/ppb_gles_chromium_texture_mapping_dev.h",
     "dev/ppb_ime_input_event_dev.h",
     "dev/ppb_memory_dev.h",
+    "dev/ppb_opengles2ext_dev.h",
     "dev/ppb_printing_dev.h",
     "dev/ppb_text_input_dev.h",
+    "dev/ppb_trace_event_dev.h",
     "dev/ppb_truetype_font_dev.h",
     "dev/ppb_url_util_dev.h",
+    "dev/ppb_video_capture_dev.h",
     "dev/ppb_video_decoder_dev.h",
+    "dev/ppb_view_dev.h",
     "dev/ppp_network_state_dev.h",
+    "dev/ppp_printing_dev.h",
     "dev/ppp_text_input_dev.h",
+    "dev/ppp_video_capture_dev.h",
     "dev/ppp_video_decoder_dev.h",
 
     # Private interfaces.