Handle rejected promises better for workers.

Source/bindings/core/v8/WorkerScriptController.h

Index: Source/bindings/core/v8/WorkerScriptController.h
diff --git a/Source/bindings/core/v8/WorkerScriptController.h b/Source/bindings/core/v8/WorkerScriptController.h
index 8df1b75596e366df809fdb3cf1b863983b72839d..695df6b1b614d3e1fbebd7cb15ab903677443f53 100644
--- a/Source/bindings/core/v8/WorkerScriptController.h
+++ b/Source/bindings/core/v8/WorkerScriptController.h
@@ -31,6 +31,7 @@
 #ifndef WorkerScriptController_h
 #define WorkerScriptController_h
 
+#include "bindings/core/v8/RejectedPromises.h"
 #include "bindings/core/v8/ScriptValue.h"
 #include "bindings/core/v8/V8Binding.h"
 #include "wtf/OwnPtr.h"
@@ -84,6 +85,8 @@ public:
     // Used by V8 bindings:
     v8::Local<v8::Context> context() { return m_scriptState ? m_scriptState->context() : v8::Local<v8::Context>(); }
 
+    RejectedPromises* rejectedPromises() const { return m_rejectedPromises.get(); }
+
 private:
     class WorkerGlobalScopeExecutionState;
 
@@ -101,6 +104,8 @@ private:
     bool m_executionScheduledToTerminate;
     mutable Mutex m_scheduledTerminationMutex;
 
+    OwnPtrWillBePersistent<RejectedPromises> m_rejectedPromises;
+
     // |m_globalScopeExecutionState| refers to a stack object
     // that evaluate() allocates; evaluate() ensuring that the
     // pointer reference to it is removed upon returning. Hence