ppapi: implement PPB_AudioEncoder

ppapi/proxy/serialized_structs.h

Index: ppapi/proxy/serialized_structs.h
diff --git a/ppapi/proxy/serialized_structs.h b/ppapi/proxy/serialized_structs.h
index efefadebefe40b05fc3b1c66e7ac5fb833702d82..04ac3350487060399e1c9a37cf9823c10aa1ad15 100644
--- a/ppapi/proxy/serialized_structs.h
+++ b/ppapi/proxy/serialized_structs.h
@@ -13,6 +13,7 @@
 #include "build/build_config.h"
 #include "ppapi/c/dev/ppb_truetype_font_dev.h"
 #include "ppapi/c/pp_bool.h"
+#include "ppapi/c/pp_codecs.h"
 #include "ppapi/c/pp_instance.h"
 #include "ppapi/c/pp_point.h"
 #include "ppapi/c/pp_rect.h"
@@ -131,6 +132,15 @@ struct PPPDecryptor_Buffer {
   base::SharedMemoryHandle handle;
 };
 
+struct PPB_AudioEncodeParameters {
+  uint32_t channels;
+  uint32_t input_sample_rate;
+  uint32_t input_sample_size;
+  PP_AudioProfile output_profile;
+  uint32_t initial_bitrate;
+  PP_HardwareAcceleration acceleration;
+};
+
 // TODO(raymes): Make ImageHandle compatible with SerializedHandle.
 #if defined(OS_WIN)
 typedef HANDLE ImageHandle;