Replace scoped_ptr with unique_ptr in webrtc/modules/audio_processing/

BUG=webrtc:5520

Review URL: https://codereview.webrtc.org/1710483002

Cr-Commit-Position: refs/heads/master@{#11684}
diff --git a/webrtc/modules/audio_processing/echo_cancellation_impl.h b/webrtc/modules/audio_processing/echo_cancellation_impl.h
index 82ae859..fbc2bcc 100644
--- a/webrtc/modules/audio_processing/echo_cancellation_impl.h
+++ b/webrtc/modules/audio_processing/echo_cancellation_impl.h
@@ -11,8 +11,9 @@
 #ifndef WEBRTC_MODULES_AUDIO_PROCESSING_ECHO_CANCELLATION_IMPL_H_
 #define WEBRTC_MODULES_AUDIO_PROCESSING_ECHO_CANCELLATION_IMPL_H_
 
+#include <memory>
+
 #include "webrtc/base/criticalsection.h"
-#include "webrtc/base/scoped_ptr.h"
 #include "webrtc/common_audio/swap_queue.h"
 #include "webrtc/modules/audio_processing/include/audio_processing.h"
 #include "webrtc/modules/audio_processing/processing_component.h"
@@ -101,7 +102,7 @@
   std::vector<float> capture_queue_buffer_ GUARDED_BY(crit_capture_);
 
   // Lock protection not needed.
-  rtc::scoped_ptr<SwapQueue<std::vector<float>, RenderQueueItemVerifier<float>>>
+  std::unique_ptr<SwapQueue<std::vector<float>, RenderQueueItemVerifier<float>>>
       render_signal_queue_;
 };