WebAudio: Remove legacy support for numerical values for Oscillator types.

LayoutTests/webaudio/resources/oscillator-testing.js

Index: LayoutTests/webaudio/resources/oscillator-testing.js
diff --git a/LayoutTests/webaudio/resources/oscillator-testing.js b/LayoutTests/webaudio/resources/oscillator-testing.js
index ae01db8131b16418d5af9a788a2f5e64f72d2fe8..b27953d08862eca0a003051c4e5d8db20319e5e5 100644
--- a/LayoutTests/webaudio/resources/oscillator-testing.js
+++ b/LayoutTests/webaudio/resources/oscillator-testing.js
@@ -17,20 +17,12 @@ var lowFrequency = 10;
 var highFrequency = nyquist + 2000; // go slightly higher than nyquist to make sure we generate silence there
 var context = 0;
 
-var OSC = {
-    SINE: 0,
-    SQUARE: 1,
-    SAWTOOTH: 2,
-    TRIANGLE: 3,
-    CUSTOM: 4,
-};
-
 function generateExponentialOscillatorSweep(oscillatorType) {
     // Create offline audio context.
     context = new OfflineAudioContext(1, sampleRate * lengthInSeconds, sampleRate);
 
     var osc = context.createOscillator();
-    if (oscillatorType == OSC.CUSTOM) {
+    if (oscillatorType == "custom") {
         // Create a simple waveform with three Fourier coefficients.
         // Note the first values are expected to be zero (DC for coeffA and Nyquist for coeffB).
         var coeffA = new Float32Array([0, 1, 0.5]);