Mac Overlays: Allow multiple overlays with sandwich strategy

cc/base/list_container.h

Index: cc/base/list_container.h
diff --git a/cc/base/list_container.h b/cc/base/list_container.h
index 305298f9d2989c5500a82c0a36603e9258b6e250..8ee4b58e853a61738b379f79c4da39c2a6c96600 100644
--- a/cc/base/list_container.h
+++ b/cc/base/list_container.h
@@ -144,7 +144,7 @@ class CC_EXPORT ListContainerBase {
 
   // Unlike the ListContainer methods, these do not invoke element destructors.
   void RemoveLast();
-  void EraseAndInvalidateAllPointers(Iterator position);
+  void EraseAndInvalidateAllPointers(Iterator* position);
   void InsertBeforeAndInvalidateAllPointers(Iterator* position,
                                             size_t number_of_elements);
 
@@ -227,10 +227,11 @@ class ListContainer : public ListContainerBase {
   // When called, all raw pointers that have been handed out are no longer
   // valid. Use with caution.
   // This function does not deallocate memory.

[ccameron, 2015/09/02 21:41:55]

I'd pass position by pointer here (to match InsertBefore's behavior below).

[Andre, 2015/09/02 21:54:51]

Hmm, but ListContainer::InsertBefore below returns an Iterator just like this.
The one that takes a pointer is ListContainerBase::InsertBefore, and I followed
that style with ListContainerBase::Erase.

[Andre, 2015/09/02 22:08:52]

Also, making it take a pointer would make code like this awkward:
https://code.google.com/p/chromium/codesearch#chromium/src/cc/base/list_conta...

[ccameron, 2015/09/02 22:22:33]

Yes, you're right, that was a bad suggestion.

Maybe add to the comment saying that the returned iterator is the element after
|position|.

[Andre, 2015/09/03 22:45:59]

Done. This was split off into another CL.

-  void EraseAndInvalidateAllPointers(Iterator position) {
+  Iterator EraseAndInvalidateAllPointers(Iterator position) {
     BaseElementType* item = *position;
     item->~BaseElementType();
-    ListContainerBase::EraseAndInvalidateAllPointers(position);
+    ListContainerBase::EraseAndInvalidateAllPointers(&position);
+    return position;
   }
 
   ConstReverseIterator crbegin() const {