Refactor the Get*Hardware* routines a bit.

content/renderer/media/audio_device.h

Index: content/renderer/media/audio_device.h
===================================================================
--- content/renderer/media/audio_device.h	(revision 110480)
+++ content/renderer/media/audio_device.h	(working copy)
@@ -101,9 +101,6 @@
   double sample_rate() const { return sample_rate_; }
   size_t buffer_size() const { return buffer_size_; }
 
-  static double GetAudioHardwareSampleRate();
-  static size_t GetAudioHardwareBufferSize();
-
   // Methods called on IO thread ----------------------------------------------
   // AudioMessageFilter::Delegate methods, called by AudioMessageFilter.
   virtual void OnRequestPacket(AudioBuffersState buffers_state);
@@ -175,4 +172,26 @@
   DISALLOW_IMPLICIT_CONSTRUCTORS(AudioDevice);
 };
 
+// Contains static methods to query hardware properties from the browser

[henrika (OOO until Aug 14), 2011/11/17 12:27:44]

Namespace perhaps?

+// process. Values are cached to avoid unnecessary round trips, but the cache
+// can be cleared if needed (currently only used by tests).
+class CONTENT_EXPORT AudioHardware {
+ public:
+  static double GetOutputSampleRate();
+  static double GetInputSampleRate();
+  static size_t GetOutputBufferSize();
+
+  // Forces the next call to any of the Get functions to query the hardware
+  // and repopulate the cache.
+  static void ResetCache();
+
+ private:
+  static double output_sample_rate_;
+  static double input_sample_rate_;
+  static size_t output_buffer_size_;
+
+  // This class doesn't support construction.
+  DISALLOW_COPY_AND_ASSIGN(AudioHardware);
+};
+
 #endif  // CONTENT_RENDERER_MEDIA_AUDIO_DEVICE_H_