Move themes garbage-collection out of shutdown code.

chrome/browser/themes/browser_theme_provider.h

Index: chrome/browser/themes/browser_theme_provider.h
diff --git a/chrome/browser/themes/browser_theme_provider.h b/chrome/browser/themes/browser_theme_provider.h
index a47f39c067e0194da8d896f8bab9dbdc833e3b02..2322b8b329922ef6a5f01a885cf7ed70f1ad94f0 100644
--- a/chrome/browser/themes/browser_theme_provider.h
+++ b/chrome/browser/themes/browser_theme_provider.h
@@ -205,6 +205,9 @@ class BrowserThemeProvider : public NonThreadSafe,
   // Returns the set of IDR_* resources that should be tinted.
   static const std::set<int>& GetTintableToolbarButtons();
 
+  // Remove preference values for themes that are no longer in use.
+  void RemoveUnusedThemes();
+
   // Save the images to be written to disk, mapping file path to id.
   typedef std::map<FilePath, int> ImagesDiskCache;
 
@@ -247,9 +250,6 @@ class BrowserThemeProvider : public NonThreadSafe,
   // case we don't have a theme pack).
   void BuildFromExtension(const Extension* extension);
 
-  // Remove preference values for themes that are no longer in use.
-  void RemoveUnusedThemes();
-
 #if defined(TOOLKIT_USES_GTK)
   // Loads an image and flips it horizontally if |rtl_enabled| is true.
   GdkPixbuf* GetPixbufImpl(int id, bool rtl_enabled) const;