Support for AudioContextOptions latencyHint.

third_party/WebKit/Source/modules/webaudio/AudioContext.idl

Index: third_party/WebKit/Source/modules/webaudio/AudioContext.idl
diff --git a/third_party/WebKit/Source/modules/webaudio/AudioContext.idl b/third_party/WebKit/Source/modules/webaudio/AudioContext.idl
index bd5f9ed7501e970be566fb592bef7b180a90a1b4..c8297b2a9170ef8c3e0dd148a8b254420537dff9 100644
--- a/third_party/WebKit/Source/modules/webaudio/AudioContext.idl
+++ b/third_party/WebKit/Source/modules/webaudio/AudioContext.idl
@@ -24,10 +24,16 @@
  * DAMAGE.
  */
 
+enum AudioContextLatencyCategory {
+    "balanced",
+    "interactive",
+    "playback"
+};
+
 // See https://webaudio.github.io/web-audio-api/#AudioContext
 [
     ActiveScriptWrappable,
-    Constructor,
+    Constructor(optional AudioContextOptions contextOptions),
     ConstructorCallWith=Document,
     DependentLifetime,
     RaisesException=Constructor,
@@ -39,6 +45,10 @@
     // Output timestamp
     [MeasureAs=AudioContextGetOutputTimestamp, CallWith=ScriptState] AudioTimestamp getOutputTimestamp();
 
+    // Number of seconds of processing latency incurred by the AudioContext
+    // passing the audio from the AudioDestinationNode to the audio subsystem
+    readonly attribute double baseLatency;
+
     // Sources
     // TODO(rtoy): The following methods should be here instead of in BaseAudioContext:
     //