Add test cases for panel overflow handling.

chrome/browser/ui/panels/panel_overflow_strip.h

Index: chrome/browser/ui/panels/panel_overflow_strip.h
diff --git a/chrome/browser/ui/panels/panel_overflow_strip.h b/chrome/browser/ui/panels/panel_overflow_strip.h
index 0dab64d9e21054d7090ccd8f2c2268a659ab5b07..1fbd12a5d2d442e713b9853b1dea0d2fb1c2ff18 100644
--- a/chrome/browser/ui/panels/panel_overflow_strip.h
+++ b/chrome/browser/ui/panels/panel_overflow_strip.h
@@ -51,16 +51,28 @@ class PanelOverflowStrip : public PanelMouseWatcherObserver,
   Panel* first_panel() const {
     return panels_.empty() ? NULL : panels_.front();
   }
+  const Panels& panels() const { return panels_; }
 
 #ifdef UNIT_TEST
-  const Panels& panels() const { return panels_; }
+  void set_max_visible_panels(int max_visible_panels) {
+    max_visible_panels_ = max_visible_panels;
+  }
+
+  bool TestShouldShowOverflowTitles(const gfx::Point& mouse_position) const {

[jennb, 2011/12/08 23:52:00]

Use a TestPanelMouseWatcher instance and simulate mouse move instead of adding
API. See other tests in panel_browsertest.cc for examples.

[jianli, 2011/12/09 22:39:07]

I've already used TestPanelMouseWatcher that. But unfortunately it is not enough
to cover the cases I want to test. I want to check if the expanded overflow area
is still shown when the mouse moves to any other point within this area.

+    return ShouldShowOverflowTitles(mouse_position);
+  }
 #endif
 
+  // The width of the overflow area that is expanded to show more info, i.e.
+  // titles, when the mouse hovers over the area.
+  static const int kOverflowAreaHoverWidth = 200;
+
  private:
   // Overridden from PanelMouseWatcherObserver:
   virtual void OnMouseMove(const gfx::Point& mouse_position) OVERRIDE;
 
   // Overridden from AnimationDelegate:
+  virtual void AnimationEnded(const ui::Animation* animation) OVERRIDE;
   virtual void AnimationProgressed(const ui::Animation* animation) OVERRIDE;
 
   void DoRefresh(size_t start_index, size_t end_index);
@@ -86,6 +98,9 @@ class PanelOverflowStrip : public PanelMouseWatcherObserver,
  // in the panel strip.
   gfx::Rect display_area_;
 
+  // Maximium number of overflow panels allowed to be shown.
+  int max_visible_panels_;
+
   // For mouse hover-over effect.
   bool are_overflow_titles_shown_;
   scoped_ptr<ui::SlideAnimation> overflow_hover_animator_;