[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 1452a9a8e0ba7dcdf216ef9cf9a911967f42c50f..37e951f51431f3db95dce34dc73919cbc1fe8573 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"
@@ -135,8 +136,10 @@ class ThemeService : public base::NonThreadSafe,
   // destroyed, uninstalls all themes that aren't the currently selected.
   void OnInfobarDestroyed();
 
-  // Remove preference values for themes that are no longer in use.
-  void RemoveUnusedThemes();
+  // Uninstall theme extensions which are no longer in use. |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.
@@ -185,14 +188,17 @@ class ThemeService : public base::NonThreadSafe,
  private:
   friend class theme_service_internal::ThemeServiceTest;
 
-  // Replaces the current theme supplier with a new one and calls
-  // StopUsingTheme() or StartUsingTheme() as appropriate.
-  void SwapThemeSupplier(scoped_refptr<CustomThemeSupplier> theme_supplier);
+  // Called when the extension service is ready.
+  void OnExtensionServiceReady();
 
   // Migrate the theme to the new theme pack schema by recreating the data pack
   // from the extension.
   void MigrateTheme();
 
+  // Replaces the current theme supplier with a new one and calls
+  // StopUsingTheme() or StartUsingTheme() as appropriate.
+  void SwapThemeSupplier(scoped_refptr<CustomThemeSupplier> theme_supplier);
+
   // Saves the filename of the cached theme pack.
   void SavePackName(const base::FilePath& pack_path);
 
@@ -240,6 +246,13 @@ class ThemeService : public base::NonThreadSafe,
 
   scoped_refptr<CustomThemeSupplier> theme_supplier_;
 
+  // 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_;
+
   // The number of infobars currently displayed.
   int number_of_infobars_;
 
@@ -247,6 +260,8 @@ class ThemeService : public base::NonThreadSafe,
 
   scoped_ptr<ThemeSyncableService> theme_syncable_service_;
 
+  base::WeakPtrFactory<ThemeService> weak_ptr_factory_;
+
   DISALLOW_COPY_AND_ASSIGN(ThemeService);
 };