Implement suspend() and resume() for OfflineAudioContext

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

Index: third_party/WebKit/Source/modules/webaudio/DeferredTaskHandler.cpp
diff --git a/third_party/WebKit/Source/modules/webaudio/DeferredTaskHandler.cpp b/third_party/WebKit/Source/modules/webaudio/DeferredTaskHandler.cpp
index 3086c030ed1089027ec42a1bdaa6c1cdcd7ca518..ed32c4bd17218ef12012a149330935317583758a 100644
--- a/third_party/WebKit/Source/modules/webaudio/DeferredTaskHandler.cpp
+++ b/third_party/WebKit/Source/modules/webaudio/DeferredTaskHandler.cpp
@@ -28,6 +28,7 @@
 
 #include "modules/webaudio/AudioNode.h"
 #include "modules/webaudio/AudioNodeOutput.h"
+#include "modules/webaudio/OfflineAudioContext.h"
 #include "platform/ThreadSafeFunctional.h"
 #include "public/platform/Platform.h"
 #include "wtf/MainThread.h"
@@ -60,6 +61,17 @@ void DeferredTaskHandler::unlock()
     m_contextGraphMutex.unlock();
 }
 
+void DeferredTaskHandler::offlineLock()
+{
+    // RELEASE_ASSERT is here to make sure to explicitly crash if this is called
+    // from other than the offline render thread, which is considered as the
+    // audio thread in OfflineAudioContext.
+    RELEASE_ASSERT_WITH_MESSAGE(isAudioThread(),
+        "DeferredTaskHandler::offlineLock() must be called within the offline audio thread.");
+
+    m_contextGraphMutex.lock();
+}
+
 #if ENABLE(ASSERT)
 bool DeferredTaskHandler::isGraphOwner()
 {
@@ -232,6 +244,12 @@ DeferredTaskHandler::AutoLocker::AutoLocker(AbstractAudioContext* context)
     m_handler.lock();
 }
 
+DeferredTaskHandler::OfflineGraphAutoLocker::OfflineGraphAutoLocker(OfflineAudioContext* context)
+    : m_handler(context->deferredTaskHandler())
+{
+    m_handler.offlineLock();
+}
+
 void DeferredTaskHandler::addRenderingOrphanHandler(PassRefPtr<AudioHandler> handler)
 {
     ASSERT(handler);