[Extensions] Add logic for when to show the toolbar redesign bubble.

chrome/browser/ui/toolbar/toolbar_actions_bar.h

Index: chrome/browser/ui/toolbar/toolbar_actions_bar.h
diff --git a/chrome/browser/ui/toolbar/toolbar_actions_bar.h b/chrome/browser/ui/toolbar/toolbar_actions_bar.h
index 6047f2427caf169ab5f0d76a18685463d20dd32c..3a6798fc29a10a08f7d57583cb485b201263c7ec 100644
--- a/chrome/browser/ui/toolbar/toolbar_actions_bar.h
+++ b/chrome/browser/ui/toolbar/toolbar_actions_bar.h
@@ -17,6 +17,10 @@ namespace extensions {
 class Extension;
 }
 
+namespace user_prefs {
+class PrefRegistrySyncable;
+}
+
 class ToolbarActionsBarDelegate;
 class ToolbarActionViewController;
 
@@ -73,6 +77,9 @@ class ToolbarActionsBar : public extensions::ExtensionToolbarModel::Observer,
   // Returns the height of a browser action icon.
   static int IconHeight();
 
+  // Registers profile preferences.
+  static void RegisterProfilePrefs(user_prefs::PrefRegistrySyncable* registry);
+
   // Returns the preferred size for the toolbar; this does *not* reflect any
   // animations that may be running.
   gfx::Size GetPreferredSize() const;
@@ -170,6 +177,7 @@ class ToolbarActionsBar : public extensions::ExtensionToolbarModel::Observer,
   Browser* GetBrowser() override;
 
   // ToolbarActionsBarBubbleDelegate:
+  void OnToolbarActionsBarBubbleShown() override;
   void OnToolbarActionsBarBubbleClosed(CloseAction action) override;
 
   // Resizes the delegate (if necessary) to the preferred size using the given