AudioContext.decodeAudioData returns a Promise

Source/modules/webaudio/AudioContext.cpp

Index: Source/modules/webaudio/AudioContext.cpp
diff --git a/Source/modules/webaudio/AudioContext.cpp b/Source/modules/webaudio/AudioContext.cpp
index ebab3b8851a59fb698968cac7c46e373c5966ed7..c3d6fde4e7e2f05b1b7b3da6bf0b50954ca34007 100644
--- a/Source/modules/webaudio/AudioContext.cpp
+++ b/Source/modules/webaudio/AudioContext.cpp
@@ -160,6 +160,7 @@ AudioContext::~AudioContext()
     ASSERT(!m_suspendResolvers.size());
     ASSERT(!m_isResolvingResumePromises);
     ASSERT(!m_resumeResolvers.size());
+    ASSERT(!m_audioDecoderResolvers.size());
 }
 
 void AudioContext::initialize()
@@ -272,20 +273,34 @@ AudioBuffer* AudioContext::createBuffer(unsigned numberOfChannels, size_t number
     return AudioBuffer::create(numberOfChannels, numberOfFrames, sampleRate, exceptionState);
 }
 
-void AudioContext::decodeAudioData(DOMArrayBuffer* audioData, AudioBufferCallback* successCallback, AudioBufferCallback* errorCallback, ExceptionState& exceptionState)
+ScriptPromise AudioContext::decodeAudioData(ScriptState* scriptState, DOMArrayBuffer* audioData, AudioBufferCallback* successCallback, AudioBufferCallback* errorCallback, ExceptionState& exceptionState)
 {
     if (isContextClosed()) {
-        throwExceptionForClosedState(exceptionState);
-        return;
+        return ScriptPromise::rejectWithDOMException(
+            scriptState,
+            DOMException::create(
+                InvalidStateError,
+                "AudioContext has been closed."));
     }
 
     if (!audioData) {
-        exceptionState.throwDOMException(
-            SyntaxError,
-            "invalid ArrayBuffer for audioData.");
-        return;
+        if (errorCallback)
+            errorCallback->handleEvent(nullptr);
+        return ScriptPromise::rejectWithDOMException(
+            scriptState,
+            DOMException::create(
+                NotSupportedError,
+                "invalid ArrayBuffer for audioData."));
     }
-    m_audioDecoder.decodeAsync(audioData, sampleRate(), successCallback, errorCallback);
+
+    RefPtrWillBeRawPtr<ScriptPromiseResolver> resolver = ScriptPromiseResolver::create(scriptState);
+    ScriptPromise promise = resolver->promise();
+
+    m_audioDecoderResolvers.append(resolver);
+
+    m_audioDecoder.decodeAsync(audioData, sampleRate(), successCallback, errorCallback, resolver.get(), this);
+
+    return promise;
 }
 
 AudioBufferSourceNode* AudioContext::createBufferSource(ExceptionState& exceptionState)
@@ -948,6 +963,19 @@ void AudioContext::handleStoppableSourceNodes()
         }
     }
 }
+
+void AudioContext::removeAudioDecoderResolver(ScriptPromiseResolver* resolver)
+{
+    ASSERT(isMainThread());
+
+    for (size_t k = 0; k < m_audioDecoderResolvers.size(); ++k) {
+        if (resolver == m_audioDecoderResolvers.at(k)) {
+            m_audioDecoderResolvers.remove(k);
+            break;
+        }
+    }
+}
+
 void AudioContext::handlePreRenderTasks()
 {
     ASSERT(isAudioThread());
@@ -1198,8 +1226,7 @@ void AudioContext::rejectPendingResolvers()
 {
     ASSERT(isMainThread());
 
-    // Audio context is closing down so reject any suspend or resume promises that are still
-    // pending.
+    // Audio context is closing down so reject any promises that are still pending.
 
     for (auto& resolver : m_suspendResolvers) {
         resolver->reject(DOMException::create(InvalidStateError, "Audio context is going away"));
@@ -1211,6 +1238,11 @@ void AudioContext::rejectPendingResolvers()
     }
     m_resumeResolvers.clear();
     m_isResolvingResumePromises = false;
+
+    for (auto& resolver : m_audioDecoderResolvers) {
+        resolver->reject(DOMException::create(InvalidStateError, "Audio context is going away"));
+    }
+    m_audioDecoderResolvers.clear();
 }
 
 const AtomicString& AudioContext::interfaceName() const
@@ -1273,6 +1305,7 @@ void AudioContext::fireCompletionEvent()
 
 DEFINE_TRACE(AudioContext)
 {
+    visitor->trace(m_audioDecoderResolvers);
     visitor->trace(m_closeResolver);
     visitor->trace(m_offlineResolver);
     visitor->trace(m_renderTarget);