Improve and unify Mac OS X run-time version checks

media/audio/mac/audio_manager_mac.cc

 // Copyright (c) 2011 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 <CoreAudio/AudioHardware.h>
 
-#include "base/sys_info.h"
+#include "base/mac/mac_util.h"
 #include "media/audio/fake_audio_input_stream.h"
 #include "media/audio/fake_audio_output_stream.h"
 #include "media/audio/mac/audio_input_mac.h"
 #include "media/audio/mac/audio_low_latency_output_mac.h"
 #include "media/audio/mac/audio_manager_mac.h"
 #include "media/audio/mac/audio_output_mac.h"
 #include "media/base/limits.h"
 
 static const int kMaxInputChannels = 2;
 
 // Maximum number of output streams that can be open simultaneously.
 static const size_t kMaxOutputStreams = 50;
 
 // By experiment the maximum number of audio streams allowed in Leopard
 // is 18. But we put a slightly smaller number just to be safe.
 static const size_t kMaxOutputStreamsLeopard = 15;
 
 // Initialized to ether |kMaxOutputStreams| or |kMaxOutputStreamsLeopard|.
 static size_t g_max_output_streams = 0;
 
 // Returns the number of audio streams allowed. This is a practical limit to
 // prevent failure caused by too many audio streams opened.
 static size_t GetMaxAudioOutputStreamsAllowed() {
   if (g_max_output_streams == 0) {
     // We are hitting a bug in Leopard where too many audio streams will cause
     // a deadlock in the AudioQueue API when starting the stream. Unfortunately
     // there's no way to detect it within the AudioQueue API, so we put a
     // special hard limit only for Leopard.
     // See bug: http://crbug.com/30242
-    int32 major, minor, bugfix;
-    base::SysInfo::OperatingSystemVersionNumbers(&major, &minor, &bugfix);
-    if (major < 10 || (major == 10 && minor <= 5)) {
+    if (base::mac::IsOSLeopardOrEarlier()) {
       g_max_output_streams = kMaxOutputStreamsLeopard;
     } else {
       // In OS other than OSX Leopard, the number of audio streams
       // allowed is a lot more.
       g_max_output_streams = kMaxOutputStreams;
     }
   }
 
   return g_max_output_streams;
 }
@@ skipping 100 matching lines @@
 
 // Called by the stream when it has been released by calling Close().
 void AudioManagerMac::ReleaseInputStream(PCMQueueInAudioInputStream* stream) {
   delete stream;
 }
 
 // static
 AudioManager* AudioManager::CreateAudioManager() {
   return new AudioManagerMac();
 }