Move the exception logic to the AudioNode creator

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

Index: third_party/WebKit/Source/modules/webaudio/DelayNode.cpp
diff --git a/third_party/WebKit/Source/modules/webaudio/DelayNode.cpp b/third_party/WebKit/Source/modules/webaudio/DelayNode.cpp
index bbe233fa531061e9ee5ed7e869576c0aebe15e30..b8d530f9d717fffed13c4e578de5be7ccfbc3cfb 100644
--- a/third_party/WebKit/Source/modules/webaudio/DelayNode.cpp
+++ b/third_party/WebKit/Source/modules/webaudio/DelayNode.cpp
@@ -34,15 +34,38 @@ namespace blink {
 
 const double maximumAllowedDelayTime = 180;
 
-DelayNode::DelayNode(AbstractAudioContext& context, float sampleRate, double maxDelayTime)
+DelayNode::DelayNode(AbstractAudioContext& context, double maxDelayTime)
     : AudioNode(context)
     , m_delayTime(AudioParam::create(context, ParamTypeDelayDelayTime, 0.0, 0.0, maxDelayTime))
 {
-    setHandler(AudioBasicProcessorHandler::create(AudioHandler::NodeTypeDelay, *this, sampleRate, adoptPtr(new DelayProcessor(sampleRate, 1, m_delayTime->handler(), maxDelayTime))));
+    setHandler(AudioBasicProcessorHandler::create(
+        AudioHandler::NodeTypeDelay,
+        *this,
+        context.sampleRate(),
+        adoptPtr(new DelayProcessor(
+            context.sampleRate(),
+            1,
+            m_delayTime->handler(),
+            maxDelayTime))));
 }
 
-DelayNode* DelayNode::create(AbstractAudioContext& context, float sampleRate, double maxDelayTime, ExceptionState& exceptionState)
+DelayNode* DelayNode::create(AbstractAudioContext& context, ExceptionState& exceptionState)
 {
+    DCHECK(isMainThread());
+
+    // The default maximum delay time for the delay node is 1 sec.
+    return create(context, 1, exceptionState);
+}
+
+DelayNode* DelayNode::create(AbstractAudioContext& context, double maxDelayTime, ExceptionState& exceptionState)
+{
+    DCHECK(isMainThread());
+
+    if (context.isContextClosed()) {
+        context.throwExceptionForClosedState(exceptionState);
+        return nullptr;
+    }
+
     if (maxDelayTime <= 0 || maxDelayTime >= maximumAllowedDelayTime) {
         exceptionState.throwDOMException(
             NotSupportedError,
@@ -55,7 +78,8 @@ DelayNode* DelayNode::create(AbstractAudioContext& context, float sampleRate, do
                 ExceptionMessages::ExclusiveBound));
         return nullptr;
     }
-    return new DelayNode(context, sampleRate, maxDelayTime);
+
+    return new DelayNode(context, maxDelayTime);
 }
 
 AudioParam* DelayNode::delayTime()