Bug 1230034 part 5 - Convert all frame properties which use DeleteValue and ReleaseValue as destructor to be typesafe. r=dbaron

By changing signature of those two functions, we make compiler complain about
all their existing uses, so we can find all of them and convert them.

Some of the callsites of Get() with those properties are also converted, but not
all of them. It is fine because if there is any incorrect conversion, compilers
is able to find out now. So they are completely typesafe.

layout/forms/nsTextControlFrame.cpp

@@ -1238,8 +1238,7 @@ nsTextControlFrame::SetInitialChildList(ChildListID     aListID,
     NS_ASSERTION(txtCtrl, "Content not a text control element");
     txtCtrl->InitializeKeyboardEventListeners();
 
-    nsPoint* contentScrollPos = static_cast<nsPoint*>
-      (Properties().Get(ContentScrollPos()));
+    nsPoint* contentScrollPos = Properties().Get(ContentScrollPos());
     if (contentScrollPos) {
       // If we have a scroll pos stored to be passed to our anonymous
       // div, do it here!