Fix media/base 64-bit compilation issues

media/base/audio_bus.cc

 // Copyright (c) 2012 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 "media/base/audio_bus.h"
 
 #include <limits>
 
 #include "base/logging.h"
 #include "media/audio/audio_parameters.h"
@@ skipping 72 matching lines @@
       if (sample > kMaxValue)
         sample = kMaxValue;
       else if (sample < kMinValue)
         sample = kMinValue;
 
       dest[offset] = static_cast<Format>(sample) + kBias;
     }
   }
 }
 
-static void ValidateConfig(int channels, int frames) {
+static void ValidateConfig(size_t channels, int frames) {
   CHECK_GT(frames, 0);
-  CHECK_GT(channels, 0);
-  CHECK_LE(channels, limits::kMaxChannels);
+  CHECK_LE(channels, static_cast<size_t>(limits::kMaxChannels));
 }
 
 static void CheckOverflow(int start_frame, int frames, int total_frames) {
   CHECK_GE(start_frame, 0);
   CHECK_GE(frames, 0);
   CHECK_GT(total_frames, 0);
   int sum = start_frame + frames;
   CHECK_LE(sum, total_frames);
   CHECK_GE(sum, 0);
 }
@@ skipping 192 matching lines @@
   CHECK_EQ(channels(), dest->channels());
   CHECK_EQ(frames(), dest->frames());
 
   // Since we don't know if the other AudioBus is wrapped or not (and we don't
   // want to care), just copy using the public channel() accessors.
   for (int i = 0; i < channels(); ++i)
     memcpy(dest->channel(i), channel(i), sizeof(*channel(i)) * frames());
 }
 
 }  // namespace media