Split MoveReadPosition into Forward and Backward versions.

webrtc/common_audio/audio_ring_buffer_unittest.cc

 /*
  *  Copyright (c) 2015 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
@@ skipping 80 matching lines @@
 
 TEST_F(AudioRingBufferTest, MoveReadPosition) {
   const size_t kNumChannels = 1;
   const float kInputArray[] = {1, 2, 3, 4};
   const size_t kNumFrames = sizeof(kInputArray) / sizeof(*kInputArray);
   ChannelBuffer<float> input(kNumFrames, kNumChannels);
   input.SetDataForTesting(kInputArray, kNumFrames);
   AudioRingBuffer buf(kNumChannels, kNumFrames);
   buf.Write(input.channels(), kNumChannels, kNumFrames);
 
-  buf.MoveReadPosition(3);
+  buf.MoveReadPositionForward(3);
   ChannelBuffer<float> output(1, kNumChannels);
   buf.Read(output.channels(), kNumChannels, 1);
   EXPECT_EQ(4, output.channels()[0][0]);
-  buf.MoveReadPosition(-3);
+  buf.MoveReadPositionBackward(3);
   buf.Read(output.channels(), kNumChannels, 1);
   EXPECT_EQ(2, output.channels()[0][0]);
 }
 
 }  // namespace webrtc