Add a name attribute for each AudioParam

third_party/WebKit/Source/modules/webaudio/AudioParam.h

Index: third_party/WebKit/Source/modules/webaudio/AudioParam.h
diff --git a/third_party/WebKit/Source/modules/webaudio/AudioParam.h b/third_party/WebKit/Source/modules/webaudio/AudioParam.h
index ca19b338b1091abac85586456c6d1638ab53e32a..54665b17615ee4adda2d9d24f17a734bd66a6bde 100644
--- a/third_party/WebKit/Source/modules/webaudio/AudioParam.h
+++ b/third_party/WebKit/Source/modules/webaudio/AudioParam.h
@@ -52,12 +52,38 @@ class AudioNodeOutput;
 // dies.
 class AudioParamHandler final : public ThreadSafeRefCounted<AudioParamHandler>, public AudioSummingJunction {
 public:
+    // Each AudioParam gets an identifier here.  This is mostly for instrospection if warnings or

[hongchan, 2016/04/29 22:22:26]

I believe you're following the conversion of AudioHandler::NodeType, but I think
this enum should be a part of AudioParam, not handler. I believe any user-facing
feature conceptually belongs to AudioParam.

Or we can put this enum under the blink namespace. (i.e. blink::AudioParamType)

[Raymond Toy, 2016/04/29 22:39:55]

That's fine with me.

[Raymond Toy, 2016/04/29 23:00:11]

Oh, this isn't user-facing.  Or at least as much user-facing as
AudioHandler::NodeType.

+    // other messages need to be printed. It's useful to know what the AudioParam represents.  The
+    // name should include the node type and the name of the AudioParam.
+    enum ParamType {
+        AudioBufferSourcePlaybackRate,
+        AudioBufferSourceDetune,
+        BiquadFilterFrequency,
+        BiquadFilterQ,
+        BiquadFilterGain,
+        BiquadFilterDetune,
+        DelayDelayTime,
+        DynamicsCompressorThreshold,
+        DynamicsCompressorKnee,
+        DynamicsCompressorRatio,
+        DynamicsCompressorAttack,
+        DynamicsCompressorRelease,
+        GainGain,
+        OscillatorFrequency,
+        OscillatorDetune,
+        StereoPannerPan

[hongchan, 2016/04/29 22:22:27]

Perhaps we need:
PannerPosition{X, Y, Z}
PannerOrientation{X, Y, Z}

[Raymond Toy, 2016/04/29 22:39:55]

Except we don't have those yet. :-)

+    };
+
+    ParamType getParamType() const { return m_paramType; }
+    // Return a nice name for the AudioParam.
+    String getParamName() const;
+
     static const double DefaultSmoothingConstant;
     static const double SnapThreshold;
 
-    static PassRefPtr<AudioParamHandler> create(AbstractAudioContext& context, double defaultValue)
+    static PassRefPtr<AudioParamHandler> create(AbstractAudioContext& context, ParamType paramType, double defaultValue)
     {
-        return adoptRef(new AudioParamHandler(context, defaultValue));
+        return adoptRef(new AudioParamHandler(context, paramType, defaultValue));
     }
 
     // This should be used only in audio rendering thread.
@@ -102,8 +128,9 @@ public:
 
     float intrinsicValue() const { return noBarrierLoad(&m_intrinsicValue); }
 private:
-    AudioParamHandler(AbstractAudioContext& context, double defaultValue)
+    AudioParamHandler(AbstractAudioContext& context, ParamType paramType, double defaultValue)
         : AudioSummingJunction(context.deferredTaskHandler())
+        , m_paramType(paramType)
         , m_intrinsicValue(defaultValue)
         , m_defaultValue(defaultValue)
         , m_smoothedValue(defaultValue)
@@ -114,6 +141,10 @@ private:
     void calculateFinalValues(float* values, unsigned numberOfValues, bool sampleAccurate);
     void calculateTimelineValues(float* values, unsigned numberOfValues);
 
+    // The type of AudioParam, indicating what this AudioParam represents and what node it belongs
+    // to.  Mostly for informational purposes and doesn't affect implementation.
+    ParamType m_paramType;
+
     // Intrinsic value
     float m_intrinsicValue;
     void setIntrinsicValue(float newValue) { noBarrierStore(&m_intrinsicValue, newValue); }
@@ -133,13 +164,16 @@ private:
 class AudioParam final : public GarbageCollectedFinalized<AudioParam>, public ScriptWrappable {
     DEFINE_WRAPPERTYPEINFO();
 public:
-    static AudioParam* create(AbstractAudioContext&, double defaultValue);
+    static AudioParam* create(AbstractAudioContext&, AudioParamHandler::ParamType, double defaultValue);
     DECLARE_TRACE();
     // |handler| always returns a valid object.
     AudioParamHandler& handler() const { return *m_handler; }
     // |context| always returns a valid object.
     AbstractAudioContext* context() const { return m_context; }
 
+    AudioParamHandler::ParamType getParamType() const { return handler().getParamType(); }
+    String getParamName() const;
+
     float value() const;
     void setValue(float);
     float defaultValue() const;
@@ -151,7 +185,7 @@ public:
     AudioParam* cancelScheduledValues(double startTime, ExceptionState&);
 
 private:
-    AudioParam(AbstractAudioContext&, double defaultValue);
+    AudioParam(AbstractAudioContext&, AudioParamHandler::ParamType, double defaultValue);
 
     RefPtr<AudioParamHandler> m_handler;
     Member<AbstractAudioContext> m_context;