Move EmptyString, kWhitespace and the BOM to base.

ui/oak/oak_aura_window_display.cc

Index: ui/oak/oak_aura_window_display.cc
diff --git a/ui/oak/oak_aura_window_display.cc b/ui/oak/oak_aura_window_display.cc
index 18323f8766cac84e4ee6e02fe5b96d89724324c5..e751a332393ff0bcceafecbbad668c0085d09f36 100644
--- a/ui/oak/oak_aura_window_display.cc
+++ b/ui/oak/oak_aura_window_display.cc
@@ -99,7 +99,7 @@ int OakAuraWindowDisplay::RowCount() {
 
 base::string16 OakAuraWindowDisplay::GetText(int row, int column_id) {
   if (!window_)
-    return EmptyString16();
+    return base::string16();
 
   base::string16 text;
   switch (row) {
@@ -153,7 +153,7 @@ base::string16 OakAuraWindowDisplay::GetText(int row, int column_id) {
       NOTREACHED();
       break;
   }
-  return EmptyString16();
+  return base::string16();
 }
 
 void OakAuraWindowDisplay::SetObserver(ui::TableModelObserver* observer) {