Revert of Replace scoped_ptr with unique_ptr in webrtc/common_audio/

webrtc/common_audio/audio_ring_buffer_unittest.cc

Index: webrtc/common_audio/audio_ring_buffer_unittest.cc
diff --git a/webrtc/common_audio/audio_ring_buffer_unittest.cc b/webrtc/common_audio/audio_ring_buffer_unittest.cc
index c5c38de56db4f82f3868ee2a54b09b57980f94bb..a7a6a9442bca8d0f83641b7652b71a58a83e6950 100644
--- a/webrtc/common_audio/audio_ring_buffer_unittest.cc
+++ b/webrtc/common_audio/audio_ring_buffer_unittest.cc
@@ -7,8 +7,6 @@
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
-
-#include <memory>
 
 #include "webrtc/common_audio/audio_ring_buffer.h"
 
@@ -29,7 +27,7 @@
   const size_t num_channels = input.num_channels();
   const size_t total_frames = input.num_frames();
   AudioRingBuffer buf(num_channels, buffer_frames);
-  std::unique_ptr<float* []> slice(new float*[num_channels]);
+  rtc::scoped_ptr<float* []> slice(new float* [num_channels]);
 
   size_t input_pos = 0;
   size_t output_pos = 0;