Change the cpp wrappers of audio input/video capture to use CompletionCallbackWithOutput.

ppapi/examples/audio_input/audio_input.cc

 // 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.
 
 #include <string.h>
 
 #include <algorithm>
 #include <limits>
 #include <vector>
 
@@ skipping 75 matching lines @@
     if (!BindGraphics(device_context_))
       return;
 
     Paint();
   }
 
   virtual void HandleMessage(const pp::Var& message_data) {
     if (message_data.is_string()) {
       std::string event = message_data.AsString();
       if (event == "PageInitialized") {
-        pp::CompletionCallback callback = callback_factory_.NewCallback(
-            &MyInstance::EnumerateDevicesFinished);
-        int32_t result = audio_input_.EnumerateDevices(&devices_, callback);
+        pp::CompletionCallbackWithOutput<std::vector<pp::DeviceRef_Dev> >
+            callback = callback_factory_.NewCallbackWithOutput(
+                &MyInstance::EnumerateDevicesFinished);
+        int32_t result = audio_input_.EnumerateDevices(callback);
         if (result != PP_OK_COMPLETIONPENDING)
           PostMessage(pp::Var("EnumerationFailed"));
       } else if (event == "UseDefault") {
         Open(pp::DeviceRef_Dev());
       } else if (event == "UseDefault(v0.1)") {
         audio_input_0_1_ = audio_input_interface_0_1_->Create(
             pp_instance(), audio_input_.config().pp_resource(),
             CaptureCallback, this);
         if (audio_input_0_1_ != 0) {
           if (!audio_input_interface_0_1_->StartCapture(audio_input_0_1_))
@@ skipping 125 matching lines @@
   void Start() {
     if (!audio_input_.is_null()) {
       if (!audio_input_.StartCapture())
         PostMessage(pp::Var("StartFailed"));
     } else if (audio_input_0_1_ != 0) {
       if (!audio_input_interface_0_1_->StartCapture(audio_input_0_1_))
         PostMessage(pp::Var("StartFailed"));
     }
   }
 
-  void EnumerateDevicesFinished(int32_t result) {
+  void EnumerateDevicesFinished(int32_t result,
+                                std::vector<pp::DeviceRef_Dev>& devices) {
     static const char* const kDelimiter = "#__#";
 
     if (result == PP_OK) {
+      devices_.swap(devices);
       std::string device_names;
       for (size_t index = 0; index < devices_.size(); ++index) {
         pp::Var name = devices_[index].GetName();
         PP_DCHECK(name.is_string());
 
         if (index != 0)
           device_names += kDelimiter;
         device_names += name.AsString();
       }
       PostMessage(pp::Var(device_names));
@@ skipping 41 matching lines @@
 };
 
 namespace pp {
 
 // Factory function for your specialization of the Module object.
 Module* CreateModule() {
   return new MyModule();
 }
 
 }  // namespace pp