Prefix string16 with base:: in ui/.

ui/views/corewm/tooltip_controller_test_helper.h

Index: ui/views/corewm/tooltip_controller_test_helper.h
diff --git a/ui/views/corewm/tooltip_controller_test_helper.h b/ui/views/corewm/tooltip_controller_test_helper.h
index 58386200000add32a8aa996476d69580abe8c6ae..4451ff35fec495dc0eebf69941ec3eab21af4a36 100644
--- a/ui/views/corewm/tooltip_controller_test_helper.h
+++ b/ui/views/corewm/tooltip_controller_test_helper.h
@@ -31,7 +31,7 @@ class TooltipControllerTestHelper {
   TooltipController* controller() { return controller_; }
 
   // These are mostly cover methods for TooltipController private methods.
-  string16 GetTooltipText();
+  base::string16 GetTooltipText();
   aura::Window* GetTooltipWindow();
   void FireTooltipTimer();
   bool IsTooltipTimerRunning();
@@ -51,14 +51,16 @@ class TooltipTestView : public views::View {
   TooltipTestView();
   virtual ~TooltipTestView();
 
-  void set_tooltip_text(string16 tooltip_text) { tooltip_text_ = tooltip_text; }
+  void set_tooltip_text(base::string16 tooltip_text) {
+    tooltip_text_ = tooltip_text;
+  }
 
   // Overridden from views::View
   virtual bool GetTooltipText(const gfx::Point& p,
-                              string16* tooltip) const OVERRIDE;
+                              base::string16* tooltip) const OVERRIDE;
 
  private:
-  string16 tooltip_text_;
+  base::string16 tooltip_text_;
 
   DISALLOW_COPY_AND_ASSIGN(TooltipTestView);
 };