Add InitWidgets() phase for GTK infobars.

chrome/browser/infobars/infobar_container.h

 // Copyright (c) 2011 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_INFOBARS_INFOBAR_CONTAINER_H_
 #define CHROME_BROWSER_INFOBARS_INFOBAR_CONTAINER_H_
 
 #include <vector>
 
 #include "base/compiler_specific.h"
@@ skipping 77 matching lines @@
   // IMPORTANT: This MUST NOT result in a call back to
   // Delegate::InfoBarContainerStateChanged() unless it causes an actual
   // change, lest we infinitely recurse.
   void SetMaxTopArrowHeight(int height);
 
   // Called when a contained infobar has animated or by some other means changed
   // its height, or when it stops animating.  The container is expected to do
   // anything necessary to respond, e.g. re-layout.
   void OnInfoBarStateChanged(bool is_animating);
 
-  // Called by |infobar| to request that it be removed from the container, as it
-  // is about to delete itself.  At this point, |infobar| should already be
-  // hidden.
+  // Called by |infobar| to request that it be removed from the container.  At
+  // this point, |infobar| should already be hidden.  Once the infobar is
+  // removed, it is guaranteed to delete itself and will not be re-added again.
   void RemoveInfoBar(InfoBar* infobar);
 
   const Delegate* delegate() const { return delegate_; }
 
  protected:
   // Subclasses must call this during destruction, so that we can remove
   // infobars (which will call the pure virtual functions below) while the
   // subclass portion of |this| has not yet been destroyed.
   void RemoveAllInfoBarsForDestruction();
 
   // These must be implemented on each platform to e.g. adjust the visible
-  // object hierarchy.
+  // object hierarchy.  The first two functions should each be called exactly
+  // once during an infobar's life (see comments on RemoveInfoBar() and
+  // AddInfoBar()).
   virtual void PlatformSpecificAddInfoBar(InfoBar* infobar,
                                           size_t position) = 0;
   virtual void PlatformSpecificRemoveInfoBar(InfoBar* infobar) = 0;
   virtual void PlatformSpecificInfoBarStateChanged(bool is_animating) {}
 
  private:
   typedef std::vector<InfoBar*> InfoBars;
 
   // content::NotificationObserver:
   virtual void Observe(int type,
@@ skipping 14 matching lines @@
   size_t HideInfoBar(InfoBarDelegate* delegate, bool use_animation);
 
   // Hides all infobars in this container without animation.
   void HideAllInfoBars();
 
   // Adds |infobar| to this container before the existing infobar at position
   // |position| and calls Show() on it.  |animate| is passed along to
   // infobar->Show().  Depending on the value of |callback_status|, this calls
   // infobar->set_container(this) either before or after the call to Show() so
   // that OnInfoBarStateChanged() either will or won't be called as a result.
+  //
+  // This should be called only once for an infobar -- once it's added, it can
+  // be repeatedly shown and hidden, but not removed and then re-added (see
+  // comments on RemoveInfoBar()).
   enum CallbackStatus { NO_CALLBACK, WANT_CALLBACK };
   void AddInfoBar(InfoBar* infobar,
                   size_t position,
                   bool animate,
                   CallbackStatus callback_status);
 
   void UpdateInfoBarArrowTargetHeights();
   int ArrowTargetHeightForInfoBar(size_t infobar_index) const;
 
   content::NotificationRegistrar registrar_;
@@ skipping 12 matching lines @@
   // Extended.
   SearchModel* search_model_;
 
   // Calculated in SetMaxTopArrowHeight().
   int top_arrow_target_height_;
 
   DISALLOW_COPY_AND_ASSIGN(InfoBarContainer);
 };
 
 #endif  // CHROME_BROWSER_INFOBARS_INFOBAR_CONTAINER_H_