Oilpan: have History on the heap by default.

Source/core/events/PopStateEvent.cpp

Index: Source/core/events/PopStateEvent.cpp
diff --git a/Source/core/events/PopStateEvent.cpp b/Source/core/events/PopStateEvent.cpp
index 50712296c00a4ce3d68243b584681068660d3a04..27f601113cd59b4c00d22a17f506723b94c8133e 100644
--- a/Source/core/events/PopStateEvent.cpp
+++ b/Source/core/events/PopStateEvent.cpp
@@ -45,7 +45,7 @@ PopStateEvent::PopStateEvent(const AtomicString& type, const PopStateEventInit&
 {
 }
 
-PopStateEvent::PopStateEvent(PassRefPtr<SerializedScriptValue> serializedState, PassRefPtrWillBeRawPtr<History> history)
+PopStateEvent::PopStateEvent(PassRefPtr<SerializedScriptValue> serializedState, History* history)
     : Event(EventTypeNames::popstate, false, true)
     , m_serializedState(serializedState)
     , m_history(history)
@@ -61,7 +61,7 @@ PassRefPtrWillBeRawPtr<PopStateEvent> PopStateEvent::create()
     return adoptRefWillBeNoop(new PopStateEvent);
 }
 
-PassRefPtrWillBeRawPtr<PopStateEvent> PopStateEvent::create(PassRefPtr<SerializedScriptValue> serializedState, PassRefPtrWillBeRawPtr<History> history)
+PassRefPtrWillBeRawPtr<PopStateEvent> PopStateEvent::create(PassRefPtr<SerializedScriptValue> serializedState, History* history)
 {
     return adoptRefWillBeNoop(new PopStateEvent(serializedState, history));
 }