Move utility functions for sample rate to AudioUtilities.

Source/modules/webaudio/MediaElementAudioSourceNode.cpp

Index: Source/modules/webaudio/MediaElementAudioSourceNode.cpp
diff --git a/Source/modules/webaudio/MediaElementAudioSourceNode.cpp b/Source/modules/webaudio/MediaElementAudioSourceNode.cpp
index e0812428868b5512fb97840db09ff06ab8a6941e..6d1204232ef01854e36e41ad743c4d2b65ab41d0 100644
--- a/Source/modules/webaudio/MediaElementAudioSourceNode.cpp
+++ b/Source/modules/webaudio/MediaElementAudioSourceNode.cpp
@@ -32,13 +32,10 @@
 #include "modules/webaudio/AudioContext.h"
 #include "modules/webaudio/AudioNodeOutput.h"
 #include "platform/Logging.h"
+#include "platform/audio/AudioUtilities.h"
 #include "platform/graphics/media/MediaPlayer.h"
 #include "wtf/Locker.h"
 
-// These are somewhat arbitrary limits, but we need to do some kind of sanity-checking.
-const unsigned minSampleRate = 8000;
-const unsigned maxSampleRate = 192000;
-
 namespace blink {
 
 MediaElementAudioSourceNode* MediaElementAudioSourceNode::create(AudioContext* context, HTMLMediaElement* mediaElement)
@@ -76,7 +73,7 @@ void MediaElementAudioSourceNode::dispose()
 void MediaElementAudioSourceNode::setFormat(size_t numberOfChannels, float sourceSampleRate)
 {
     if (numberOfChannels != m_sourceNumberOfChannels || sourceSampleRate != m_sourceSampleRate) {
-        if (!numberOfChannels || numberOfChannels > AudioContext::maxNumberOfChannels() || sourceSampleRate < minSampleRate || sourceSampleRate > maxSampleRate) {
+        if (!numberOfChannels || numberOfChannels > AudioContext::maxNumberOfChannels() || !AudioUtilities::isValidAudioBufferSampleRate(sourceSampleRate)) {
             // process() will generate silence for these uninitialized values.
             WTF_LOG(Media, "MediaElementAudioSourceNode::setFormat(%u, %f) - unhandled format change", static_cast<unsigned>(numberOfChannels), sourceSampleRate);
             m_sourceNumberOfChannels = 0;