Using AudioBus::ZeroFramesPartial() instead of manual zeroing.

chrome/browser/copresence/chrome_whispernet_client_browsertest.cc

 // Copyright 2014 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 "chrome/browser/copresence/chrome_whispernet_client.h"
 
 #include <cmath>
 #include <cstdlib>
 #include <string>
 
@@ skipping 196 matching lines @@
                       base::TimeDelta /* buffer_delay */) override {
     // Copy any saved samples we have to the output bus.
     const int remaining_frames =
         saved_samples_->frames() - saved_samples_index_;
     const int frames_to_copy = std::min(remaining_frames, dest->frames());
     saved_samples_stereo_->CopyPartialFramesTo(saved_samples_index_,
                                                frames_to_copy, 0, dest);
     saved_samples_index_ += frames_to_copy;
 
     // Pad any remaining space with zeroes.
-    for (int i = remaining_frames; i < dest->frames(); i++) {
-      for (int c = 0; c < dest->channels(); c++)
-        dest->channel(c)[i] = 0;
+    if (remaining_frames < dest->frames()) {
+      dest->ZeroFramesPartial(remaining_frames,
+                              dest->frames() - remaining_frames);
     }
 
     // Return the volume level.
     return 1.0;
   }
 
   scoped_ptr<base::RunLoop> run_loop_;
   bool initialized_;
 
   std::string expected_token_;
@@ skipping 134 matching lines @@
 
   EncodeTokenAndSaveSamples(client_3.get(), true, kSixZeros, token_params);
   DecodeSamplesAndVerifyToken(client_3.get(), true, kSixZeros, token_params);
 
   const size_t kLongTokenLengths[2] = {8, 9};
   GetTokenParamsForLengths(kLongTokenLengths, token_params);
 
   EncodeTokenAndSaveSamples(client_2.get(), true, kEightZeros, token_params);
   DecodeSamplesAndVerifyToken(client_2.get(), true, kEightZeros, token_params);
 }