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

Source/core/editing/UndoStack.cpp

 /*
  * Copyright (C) 2006, 2007 Apple, Inc.  All rights reserved.
  * Copyright (C) 2012 Google, Inc.  All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
@@ skipping 27 matching lines @@
 // unbounded memory. This is the maximum number of distinct undoable
 // actions -- unbroken stretches of typed characters are coalesced
 // into a single action.
 static const size_t maximumUndoStackDepth = 1000;
 
 UndoStack::UndoStack()
     : m_inRedo(false)
 {
 }
 
-UndoStack::~UndoStack()
+DEFINE_EMPTY_DESTRUCTOR_WILL_BE_REMOVED(UndoStack)
+
+PassOwnPtrWillBeRawPtr<UndoStack> UndoStack::create()
 {
-}
-
-PassOwnPtr<UndoStack> UndoStack::create()
-{
-    return adoptPtr(new UndoStack());
+    return adoptPtrWillBeNoop(new UndoStack());
 }
 
 void UndoStack::registerUndoStep(PassRefPtrWillBeRawPtr<UndoStep> step)
 {
     if (m_undoStack.size() == maximumUndoStackDepth)
         m_undoStack.removeFirst(); // drop oldest item off the far end
     if (!m_inRedo)
         m_redoStack.clear();
     m_undoStack.append(step);
 }
 
 void UndoStack::registerRedoStep(PassRefPtrWillBeRawPtr<UndoStep> step)
 {
     m_redoStack.append(step);
 }
 
 void UndoStack::didUnloadFrame(const LocalFrame& frame)
 {
     NoEventDispatchAssertion assertNoEventDispatch;
     filterOutUndoSteps(m_undoStack, 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()) {
         UndoStep* step = stack.first().get();
         if (!step->belongsTo(frame))
             newStack.append(step);
         stack.removeFirst();
     }
     stack.swap(newStack);
 }
@@ skipping 26 matching lines @@
         RefPtrWillBeRawPtr<UndoStep> step(back->get());
         m_redoStack.remove(back);
 
         ASSERT(!m_inRedo);
         TemporaryChange<bool> redoScope(m_inRedo, true);
         step->reapply();
         // reapply will call us back to push this command onto the undo stack.
     }
 }
 
+void UndoStack::trace(Visitor* visitor)
+{
+    visitor->trace(m_undoStack);
+    visitor->trace(m_redoStack);
+}
+
 } // namesace WebCore