Introduce KeepAliveWhilePending to ScriptPromiseResolverWithContext.

Source/core/dom/ExecutionContext.h

Index: Source/core/dom/ExecutionContext.h
diff --git a/Source/core/dom/ExecutionContext.h b/Source/core/dom/ExecutionContext.h
index c93492dbf87c6e9b36290cb54605142c50bac78e..eb5290f5e847a9e6c234001ca1fd53541e280c03 100644
--- a/Source/core/dom/ExecutionContext.h
+++ b/Source/core/dom/ExecutionContext.h
@@ -29,6 +29,7 @@
 #define ExecutionContext_h
 
 #include "core/dom/ActiveDOMObject.h"
+#include "core/dom/AsyncInitializerContext.h"
 #include "core/dom/ExecutionContextClient.h"
 #include "core/dom/SandboxFlags.h"
 #include "core/dom/SecurityContext.h"
@@ -122,6 +123,8 @@ public:
 
     PassOwnPtr<LifecycleNotifier<ExecutionContext> > createLifecycleNotifier();
 
+    AsyncInitializerContext& asyncInitializerContext() { return m_asyncInitializerContext; }
+
     virtual EventQueue* eventQueue() const = 0;
 
 protected:
@@ -161,6 +164,8 @@ private:
     // ExecutionContext's members (notably m_timeouts) is called before they are destructed,
     // m_lifecycleNotifer should be placed *after* such members.
     OwnPtr<ContextLifecycleNotifier> m_lifecycleNotifier;
+
+    AsyncInitializerContext m_asyncInitializerContext;
 };
 
 } // namespace WebCore