Polish launcher tooltip visibility (2nd try).

ash/launcher/launcher_tooltip_manager.h

Index: ash/launcher/launcher_tooltip_manager.h
diff --git a/ash/launcher/launcher_tooltip_manager.h b/ash/launcher/launcher_tooltip_manager.h
index 5451ccfcd766bdf6755b246d737bf97c651f2694..673380c9e07e62cabb3d2f94b2a6c472fea2be9a 100644
--- a/ash/launcher/launcher_tooltip_manager.h
+++ b/ash/launcher/launcher_tooltip_manager.h
@@ -7,6 +7,7 @@
 #pragma once
 
 #include "ash/ash_export.h"
+#include "ash/wm/shelf_layout_manager.h"
 #include "ash/wm/shelf_types.h"
 #include "base/basictypes.h"
 #include "base/string16.h"
@@ -25,6 +26,7 @@ class Label;
 
 namespace ash {
 namespace test {
+class LauncherTooltipManagerTest;
 class LauncherViewTest;
 }
 
@@ -32,10 +34,11 @@ namespace internal {
 
 // LauncherTooltipManager manages the tooltip balloon poping up on launcher
 // items.
-class ASH_EXPORT LauncherTooltipManager {
+class ASH_EXPORT LauncherTooltipManager : public ShelfLayoutManager::Observer {
  public:
-  LauncherTooltipManager(ShelfAlignment alignment);
-  ~LauncherTooltipManager();
+  LauncherTooltipManager(ShelfAlignment alignment,
+                         ShelfLayoutManager* shelf_layout_manager);
+  virtual ~LauncherTooltipManager();
 
   // Called when the bubble is closed.
   void OnBubbleClosed(views::BubbleDelegateView* view);
@@ -63,9 +66,18 @@ class ASH_EXPORT LauncherTooltipManager {
   // Returns true if the tooltip is currently visible.
   bool IsVisible();
 
+protected:
+  // ShelfLayoutManager::Observer overrides:
+  virtual void WillDeleteShelf() OVERRIDE;
+  virtual void WillChangeVisibilityState(
+      ShelfLayoutManager::VisibilityState new_state) OVERRIDE;
+  virtual void OnAutoHideStateChanged(
+      ShelfLayoutManager::AutoHideState new_state) OVERRIDE;
+
  private:
   class LauncherTooltipBubble;
   friend class test::LauncherViewTest;
+  friend class test::LauncherTooltipManagerTest;
 
   void ShowInternal();
   void CreateBubble(views::View* anchor, const string16& text);
@@ -76,6 +88,8 @@ class ASH_EXPORT LauncherTooltipManager {
   ShelfAlignment alignment_;
   scoped_ptr<base::Timer> timer_;
 
+  ShelfLayoutManager* shelf_layout_manager_;
+
   DISALLOW_COPY_AND_ASSIGN(LauncherTooltipManager);
 };