Mac: improve apparent z-order problems when switching Spaces.

chrome/browser/cocoa/status_bubble_mac.h

 // Copyright (c) 2009 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_COCOA_STATUS_BUBBLE_MAC_H_
 #define CHROME_BROWSER_COCOA_STATUS_BUBBLE_MAC_H_
 
 #include <string>
 
 #import <Cocoa/Cocoa.h>
@@ skipping 45 matching lines @@
   // that state changes can be observed by unit tests.
   void SetState(StatusBubbleState state);
 
   // Sets the bubble text for SetStatus and SetURL.
   void SetText(const std::wstring& text, bool is_url);
 
   // Construct the window/widget if it does not already exist. (Safe to call if
   // it does.)
   void Create();
 
-  // Attaches the status bubble window to its parent window.
+  // Attaches the status bubble window to its parent window. Safe to call even
+  // when already attached.
   void Attach();
 
+  // Detaches the status bubble window from its parent window.
+  void Detach();
+
+  // Is the status bubble attached to the browser window? It should be attached
+  // when shown and during any fades, but should be detached when hidden.
+  bool is_attached() { return [window_ parentWindow] != nil; }
+
   // Begins fading the status bubble window in or out depending on the value
   // of |show|.  This must be called from the appropriate fade state,
   // kBubbleShowingFadeIn or kBubbleHidingFadeOut, or from the appropriate
   // fully-shown/hidden state, kBubbleShown or kBubbleHidden.  This may be
   // called at any point during a fade-in or fade-out; it is even possible to
   // reverse a transition before it has completed.
   void Fade(bool show);
 
   // One-shot timer operations to manage the delays associated with the
   // kBubbleShowingTimer and kBubbleHidingTimer states.  StartTimer and
@@ skipping 47 matching lines @@
 @interface NSObject(StatusBubbleDelegate)
 // Called to query the delegate about the vertical offset (if any) that should
 // be applied to the StatusBubble's position.
 - (float)verticalOffsetForStatusBubble;
 
 // Called from SetState to notify the delegate of state changes.
 - (void)statusBubbleWillEnterState:(StatusBubbleMac::StatusBubbleState)state;
 @end
 
 #endif  // #ifndef CHROME_BROWSER_COCOA_STATUS_BUBBLE_MAC_H_