Implement learn more bubble on views.

chrome/browser/ui/views/autofill/tooltip_icon.h

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CHROME_BROWSER_UI_VIEWS_AUTOFILL_TOOLTIP_ICON_H_
 #define CHROME_BROWSER_UI_VIEWS_AUTOFILL_TOOLTIP_ICON_H_
 
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
 #include "base/strings/string16.h"
+#include "base/timer/timer.h"
 #include "ui/views/controls/image_view.h"
 
-// A tooltip icon (just an ImageView with a tooltip). Looks like (?).
+namespace autofill {
+
+class InfoBubble;
+
+// A tooltip icon that shows a bubble on hover. Looks like (?).
 class TooltipIcon : public views::ImageView {
  public:
   explicit TooltipIcon(const base::string16& tooltip);
   virtual ~TooltipIcon();
 
-  // views::View implementation
-  virtual bool GetTooltipText(const gfx::Point& p,
-                              base::string16* tooltip) const OVERRIDE;
+  static const char kViewClassName[];
+
+  // views::ImageView:
+  virtual const char* GetClassName() const OVERRIDE;
+  virtual void OnMouseEntered(const ui::MouseEvent& event) OVERRIDE;
+  virtual void OnMouseExited(const ui::MouseEvent& event) OVERRIDE;
+
  private:
+  // Changes this view's image to the resource indicated by |idr|.
+  void ChangeImageTo(int idr);
+
+  // Starts a timer to hide |bubble_|.
+  void StartHideTimer();
+
+  // Helpers to hide and show |bubble_|.
+  void HideBubble();
+  void ShowBubble();
+
+  // The text to show in a bubble when hovered.
   base::string16 tooltip_;
 
+  // A bubble shown on hover. Weak; owns itself. NULL while hiding.
+  InfoBubble* bubble_;
+
+  // A timer to delay hiding |bubble_|.
+  base::OneShotTimer<TooltipIcon> hide_timer_;
+
   DISALLOW_COPY_AND_ASSIGN(TooltipIcon);
 };
 
+}  // namespace autofill
+
 #endif  // CHROME_BROWSER_UI_VIEWS_AUTOFILL_TOOLTIP_ICON_H_