Move utility functions for sample rate to AudioUtilities.

Source/platform/audio/AudioUtilities.h

Index: Source/platform/audio/AudioUtilities.h
diff --git a/Source/platform/audio/AudioUtilities.h b/Source/platform/audio/AudioUtilities.h
index a7e02d721f2435224c4081f2ff9c4f8a9b55992c..d26d01498af4846af70464f923e9abb8c6247473 100644
--- a/Source/platform/audio/AudioUtilities.h
+++ b/Source/platform/audio/AudioUtilities.h
@@ -42,6 +42,15 @@ PLATFORM_EXPORT double discreteTimeConstantForSampleRate(double timeConstant, do
 // Convert the time to a sample frame at the given sample rate.
 PLATFORM_EXPORT size_t timeToSampleFrame(double time, double sampleRate);
 
+// Check the given sample rate is supported by platform.

[Raymond Toy, 2014/09/11 16:38:45]

Be more descriptive. Something like

// Check that |sampleRate| is a valid rate for AudioBuffers.

[KhNo, 2014/09/12 15:01:05]

Done.

+PLATFORM_EXPORT bool isSampleRateRangeGood(float sampleRate);

[Raymond Toy, 2014/09/11 16:38:45]

Maybe a better name would be isValidAudioBufferSampleRate?

[KhNo, 2014/09/12 15:01:05]

Yes, it is for AudioBuffer.
I have done.

+
+// Caculates correct fftsize with the given sample rate.

[Raymond Toy, 2014/09/11 16:38:45]

Fix typo: Caculates -> Calculates.

And make it clear this is for the HRTF Panner, not just any old fft size.

And maybe rename it to hrtfFFTSizeForSampleRate to make it clearer.

Actually, I think it might be better to leave fftSizeForSampleRate in HRTFPanner
instead of moving it here.  It's really specific to the panner.

[KhNo, 2014/09/12 15:01:05]

I think you right. There is better position. I reverted it.

+PLATFORM_EXPORT size_t fftSizeForSampleRate(float sampleRate);
+
+// Renturn max/min sample rate that platform supported.

[Raymond Toy, 2014/09/11 16:38:45]

Fix typo: Renturn -> Return.

And as for isSampleRateRangeGood, state this is for AudioBuffers

[KhNo, 2014/09/12 15:01:05]

Done.

+PLATFORM_EXPORT float minAllowedSampleRate();
+PLATFORM_EXPORT float maxAllowedSampleRate();

[Raymond Toy, 2014/09/11 16:38:45]

Maybe rename these to minAudioBufferSampleRate and maxAudioBufferSampleRate?

[KhNo, 2014/09/12 15:01:05]

Done.

 } // AudioUtilites
 } // namespace blink