system tray ui change for AllowOnlyPolicyNetworksToConnect

ash/system/tray/hover_highlight_view.h

Index: ash/system/tray/hover_highlight_view.h
diff --git a/ash/system/tray/hover_highlight_view.h b/ash/system/tray/hover_highlight_view.h
index 6b9d1a22a42dada37b43bc1e360a19c348de0b48..0bf86d85240876b8ba9987e2a228434ba1769559 100644
--- a/ash/system/tray/hover_highlight_view.h
+++ b/ash/system/tray/hover_highlight_view.h
@@ -66,6 +66,10 @@ class HoverHighlightView : public ActionableView {
 
   bool hover() const { return hover_; }
 
+  bool GetTooltipText(const gfx::Point& p,
+                      base::string16* tooltip) const override;
+  void SetTooltipText(const base::string16& tooltip);
+
  protected:
   // Overridden from views::View.
   void GetAccessibleState(ui::AXViewState* state) override;
@@ -103,6 +107,7 @@ class HoverHighlightView : public ActionableView {
   bool expandable_;
   bool checkable_;
   bool checked_;
+  base::string16 tooltip_;
 
   DISALLOW_COPY_AND_ASSIGN(HoverHighlightView);
 };