Garbage Collect the Storage directory on next profile start after an extension uninstall.

content/public/browser/site_instance.h

Index: content/public/browser/site_instance.h
diff --git a/content/public/browser/site_instance.h b/content/public/browser/site_instance.h
index 69df3110e6d0c92a189d7383092132444758f85e..0696fdccdfd3c36b147a812e2e5ef344637a3c09 100644
--- a/content/public/browser/site_instance.h
+++ b/content/public/browser/site_instance.h
@@ -134,6 +134,10 @@ class CONTENT_EXPORT SiteInstance : public base::RefCounted<SiteInstance> {
   static bool IsSameWebSite(content::BrowserContext* browser_context,
                             const GURL& url1, const GURL& url2);
 
+  // Returns the site for the given URL, which includes only the scheme and
+  // registered domain.  Returns an empty GURL if the URL has no host.
+  static GURL GetSiteForURL(BrowserContext* context, const GURL& url);
+
  protected:
   friend class base::RefCounted<SiteInstance>;