Bug 1476514 store AudioContext destination stream on AudioWorkletImpl r=padenot

The destination stream will provide currentFrame for AudioWorkletGlobalScope on the worklet execution thread.

On the control thread, it supports messages via the MediaStreamGraph and identifies the associated AudioContext.

Differential Revision: https://phabricator.services.mozilla.com/D13219

--HG--
extra : moz-landing-system : lando

dom/media/webaudio/AudioWorkletImpl.cpp

@@ -7,6 +7,7 @@
 #include "AudioWorkletImpl.h"
 
 #include "AudioContext.h"
+#include "AudioNodeStream.h"
 #include "mozilla/dom/AudioWorkletBinding.h"
 #include "mozilla/dom/AudioWorkletGlobalScope.h"
 #include "mozilla/dom/Worklet.h"
@@ -31,13 +32,16 @@ namespace mozilla {
     return nullptr;
   }
 
-  RefPtr<AudioWorkletImpl> impl = new AudioWorkletImpl(window, principal);
+  RefPtr<AudioWorkletImpl> impl =
+      new AudioWorkletImpl(window, principal, aContext->DestinationStream());
   return MakeAndAddRef<dom::Worklet>(window, std::move(impl));
 }
 
 AudioWorkletImpl::AudioWorkletImpl(nsPIDOMWindowInner* aWindow,
-                                   nsIPrincipal* aPrincipal)
-    : WorkletImpl(aWindow, aPrincipal) {}
+                                   nsIPrincipal* aPrincipal,
+                                   AudioNodeStream* aDestinationStream)
+    : WorkletImpl(aWindow, aPrincipal),
+      mDestinationStream(aDestinationStream) {}
 
 AudioWorkletImpl::~AudioWorkletImpl() = default;
 

dom/media/webaudio/AudioWorkletImpl.h

@@ -11,6 +11,8 @@
 
 namespace mozilla {
 
+class AudioNodeStream;
+
 namespace dom {
 class AudioContext;
 }
@@ -30,8 +32,11 @@ class AudioWorkletImpl final : public WorkletImpl {
   already_AddRefed<dom::WorkletGlobalScope> ConstructGlobalScope() override;
 
  private:
-  AudioWorkletImpl(nsPIDOMWindowInner* aWindow, nsIPrincipal* aPrincipal);
+  AudioWorkletImpl(nsPIDOMWindowInner* aWindow, nsIPrincipal* aPrincipal,
+                   AudioNodeStream* aDestinationStream);
   ~AudioWorkletImpl();
+
+  const RefPtr<AudioNodeStream> mDestinationStream;
 };
 
 }  // namespace mozilla