[DRAFT] Allow a user to revert to their previous theme without closing infobar

chrome/browser/themes/theme_service.h

Index: chrome/browser/themes/theme_service.h
diff --git a/chrome/browser/themes/theme_service.h b/chrome/browser/themes/theme_service.h
index b6d88696267ebb318459f68a2acea6dd0b853c27..51197b0dfaec71bbbf1a12d34801746ce7efe709 100644
--- a/chrome/browser/themes/theme_service.h
+++ b/chrome/browser/themes/theme_service.h
@@ -13,6 +13,7 @@
 #include "base/compiler_specific.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
+#include "base/memory/weak_ptr.h"
 #include "base/threading/non_thread_safe.h"
 #include "components/browser_context_keyed_service/browser_context_keyed_service.h"
 #include "content/public/browser/notification_observer.h"
@@ -132,7 +133,9 @@ class ThemeService : public base::NonThreadSafe,
   void OnInfobarDestroyed();
 
   // Remove preference values for themes that are no longer in use.
-  void RemoveUnusedThemes();
+  // |ignore_infobars| is whether unused themes should be removed despite
+  // a theme infobar being visible.
+  void RemoveUnusedThemes(bool ignore_infobars);
 
   // Returns the syncable service for syncing theme. The returned service is
   // owned by |this| object.
@@ -220,10 +223,19 @@ class ThemeService : public base::NonThreadSafe,
   // The number of infobars currently displayed.
   int number_of_infobars_;
 
+  // The id of the theme extension which has just been installed but has not
+  // been loaded yet. The theme extension with |installed_pending_load_id_| may
+  // never be loaded if the install is due to updating a disabled theme.
+  // |pending_install_id_| should be set to |kDefaultThemeID| if there are no
+  // recently installed theme extensions
+  std::string installed_pending_load_id_;
+
   content::NotificationRegistrar registrar_;
 
   scoped_ptr<ThemeSyncableService> theme_syncable_service_;
 
+  base::WeakPtrFactory<ThemeService> weak_ptr_factory_;
+
   DISALLOW_COPY_AND_ASSIGN(ThemeService);
 };