Replace scoped_ptr with unique_ptr in webrtc/common_audio/

webrtc/modules/audio_processing/audio_processing_impl.cc

Index: webrtc/modules/audio_processing/audio_processing_impl.cc
diff --git a/webrtc/modules/audio_processing/audio_processing_impl.cc b/webrtc/modules/audio_processing/audio_processing_impl.cc
index f3856128bb6bbd83544c1901e25a5790d2633e95..92765a2a3c2e972db1b3b0f3ae1864ab913df10f 100644
--- a/webrtc/modules/audio_processing/audio_processing_impl.cc
+++ b/webrtc/modules/audio_processing/audio_processing_impl.cc
@@ -297,11 +297,11 @@ int AudioProcessingImpl::InitializeLocked() {
         formats_.rev_proc_format.num_channels(),
         rev_audio_buffer_out_num_frames));
     if (rev_conversion_needed()) {
-      render_.render_converter = AudioConverter::Create(
+      render_.render_converter = rtc::UniqueToScoped(AudioConverter::Create(
           formats_.api_format.reverse_input_stream().num_channels(),
           formats_.api_format.reverse_input_stream().num_frames(),
           formats_.api_format.reverse_output_stream().num_channels(),
-          formats_.api_format.reverse_output_stream().num_frames());
+          formats_.api_format.reverse_output_stream().num_frames()));
     } else {
       render_.render_converter.reset(nullptr);
     }