Prefix string16 with base:: in ui/.

ui/views/controls/progress_bar.h

Index: ui/views/controls/progress_bar.h
diff --git a/ui/views/controls/progress_bar.h b/ui/views/controls/progress_bar.h
index 1f3d595534c44ab46c5f7fbd1b70ff385d130c8f..6584dc83147216b6636ea7100cba312ee04c83c0 100644
--- a/ui/views/controls/progress_bar.h
+++ b/ui/views/controls/progress_bar.h
@@ -35,11 +35,11 @@ class VIEWS_EXPORT ProgressBar : public View {
   // Sets the tooltip text.  Default behavior for a progress bar is to show no
   // tooltip on mouse hover. Calling this lets you set a custom tooltip.  To
   // revert to default behavior, call this with an empty string.
-  void SetTooltipText(const string16& tooltip_text);
+  void SetTooltipText(const base::string16& tooltip_text);
 
   // Overridden from View:
   virtual bool GetTooltipText(const gfx::Point& p,
-                              string16* tooltip) const OVERRIDE;
+                              base::string16* tooltip) const OVERRIDE;
   virtual void GetAccessibleState(ui::AccessibleViewState* state) OVERRIDE;
 
  private:
@@ -58,7 +58,7 @@ class VIEWS_EXPORT ProgressBar : public View {
   double current_value_;
 
   // Tooltip text.
-  string16 tooltip_text_;
+  base::string16 tooltip_text_;
 
   DISALLOW_COPY_AND_ASSIGN(ProgressBar);
 };