Assert destination handler exists in AudioParam

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

Index: third_party/WebKit/Source/modules/webaudio/AudioParam.cpp
diff --git a/third_party/WebKit/Source/modules/webaudio/AudioParam.cpp b/third_party/WebKit/Source/modules/webaudio/AudioParam.cpp
index ab6894a96fabaae33bd7554d04093c22a1489831..c36bee42e9a534d50fe987adcd0c6aa22df81e6f 100644
--- a/third_party/WebKit/Source/modules/webaudio/AudioParam.cpp
+++ b/third_party/WebKit/Source/modules/webaudio/AudioParam.cpp
@@ -35,6 +35,19 @@ namespace blink {
 const double AudioParamHandler::DefaultSmoothingConstant = 0.05;
 const double AudioParamHandler::SnapThreshold = 0.001;
 
+AudioParamHandler::AudioParamHandler(AbstractAudioContext& context, AudioParamType paramType, double defaultValue)
+    : AudioSummingJunction(context.deferredTaskHandler())
+    , m_paramType(paramType)
+    , m_intrinsicValue(defaultValue)
+    , m_defaultValue(defaultValue)
+    , m_smoothedValue(defaultValue)
+{
+    // The destination MUST exist because we need the destination handler for the AudioParam.
+    RELEASE_ASSERT(context.destination());
+
+    m_destinationHandler = &context.destination()->audioDestinationHandler();
+}
+
 AudioDestinationHandler& AudioParamHandler::destinationHandler() const
 {
     return *m_destinationHandler;