Bug 448372 - Sensitive cookie data remains readable and on disk in cookies.sqlite after "Clear Private Data" and "Remove All Cookies"

This makes the cookie service now delete the database file if it cannot clear
the table because of corruption.  It then re-inits the database.
r=dwitte

netwerk/cookie/src/nsCookieService.cpp

@@ -780,15 +780,21 @@ NS_IMETHODIMP
 nsCookieService::RemoveAll()
 {
   RemoveAllFromMemory();
-  NotifyChanged(nsnull, NS_LITERAL_STRING("cleared").get());
 
   // clear the cookie file
   if (mDBConn) {
     nsresult rv = mDBConn->ExecuteSimpleSQL(NS_LITERAL_CSTRING("DELETE FROM moz_cookies"));
-    if (NS_FAILED(rv))
-      NS_WARNING("db delete failed");
+    if (NS_FAILED(rv)) {
+      // Database must be corrupted, so remove it completely.
+      nsCOMPtr<nsIFile> dbFile;
+      mDBConn->GetDatabaseFile(getter_AddRefs(dbFile));
+      mDBConn->Close();
+      dbFile->Remove(PR_FALSE);
+      InitDB();
+    }
   }
 
+  NotifyChanged(nsnull, NS_LITERAL_STRING("cleared").get());
   return NS_OK;
 }