Have EditCommand classes deal with Document references, not pointers

Source/core/editing/SetSelectionCommand.cpp

Index: Source/core/editing/SetSelectionCommand.cpp
diff --git a/Source/core/editing/SetSelectionCommand.cpp b/Source/core/editing/SetSelectionCommand.cpp
index 2c17b63b7654ef2f63c3c8ed3b51ff773f693f48..1480636f4e0b00104eae4c87fa6fe70f2610ba38 100644
--- a/Source/core/editing/SetSelectionCommand.cpp
+++ b/Source/core/editing/SetSelectionCommand.cpp
@@ -32,7 +32,7 @@
 namespace WebCore {
 
 SetSelectionCommand::SetSelectionCommand(const VisibleSelection& selection, FrameSelection::SetSelectionOptions options)
-    : SimpleEditCommand(&selection.base().anchorNode()->document())
+    : SimpleEditCommand(selection.base().anchorNode()->document())
     , m_options(options)
     , m_selectionToSet(selection)
 {
@@ -40,7 +40,7 @@ SetSelectionCommand::SetSelectionCommand(const VisibleSelection& selection, Fram
 
 void SetSelectionCommand::doApply()
 {
-    FrameSelection* selection = document()->frame()->selection();
+    FrameSelection* selection = document().frame()->selection();
     ASSERT(selection);
 
     if (selection->shouldChangeSelection(m_selectionToSet) && m_selectionToSet.isNonOrphanedCaretOrRange()) {
@@ -51,7 +51,7 @@ void SetSelectionCommand::doApply()
 
 void SetSelectionCommand::doUnapply()
 {
-    FrameSelection* selection = document()->frame()->selection();
+    FrameSelection* selection = document().frame()->selection();
     ASSERT(selection);
 
     if (selection->shouldChangeSelection(startingSelection()) && startingSelection().isNonOrphanedCaretOrRange())