Oilpan: move a page's UndoStack to the heap.

Source/core/editing/UndoStack.cpp

Index: Source/core/editing/UndoStack.cpp
diff --git a/Source/core/editing/UndoStack.cpp b/Source/core/editing/UndoStack.cpp
index cba100c46f0edb030d226b5c27d5d4b5a9fcd7e6..bc0b0a7b06069d18a76ea93122121c81163bd90e 100644
--- a/Source/core/editing/UndoStack.cpp
+++ b/Source/core/editing/UndoStack.cpp
@@ -45,13 +45,11 @@ UndoStack::UndoStack()
 {
 }
 
-UndoStack::~UndoStack()
-{
-}
+DEFINE_EMPTY_DESTRUCTOR_WILL_BE_REMOVED(UndoStack)
 
-PassOwnPtr<UndoStack> UndoStack::create()
+PassOwnPtrWillBeRawPtr<UndoStack> UndoStack::create()
 {
-    return adoptPtr(new UndoStack());
+    return adoptPtrWillBeNoop(new UndoStack());
 }
 
 void UndoStack::registerUndoStep(PassRefPtrWillBeRawPtr<UndoStep> step)
@@ -75,7 +73,7 @@ void UndoStack::didUnloadFrame(const LocalFrame& frame)
     filterOutUndoSteps(m_redoStack, frame);
 }
 
-void UndoStack::filterOutUndoSteps(WillBePersistentUndoStepStack& stack, const LocalFrame& frame)
+void UndoStack::filterOutUndoSteps(UndoStepStack& stack, const LocalFrame& frame)
 {
     UndoStepStack newStack;
     while (!stack.isEmpty()) {
@@ -122,4 +120,10 @@ void UndoStack::redo()
     }
 }
 
+void UndoStack::trace(Visitor* visitor)
+{
+    visitor->trace(m_undoStack);
+    visitor->trace(m_redoStack);
+}
+
 } // namesace WebCore