Move ErrorDelegate to its own file and add static utility functions to ErrorDelegate

chrome/browser/diagnostics/sqlite_diagnostics.h

Index: chrome/browser/diagnostics/sqlite_diagnostics.h
diff --git a/chrome/browser/diagnostics/sqlite_diagnostics.h b/chrome/browser/diagnostics/sqlite_diagnostics.h
index c416e886ce6fc8b3f1d10a197689d7878213461a..2d0345841c335fa5d1c95b9b577da813dffb3667 100644
--- a/chrome/browser/diagnostics/sqlite_diagnostics.h
+++ b/chrome/browser/diagnostics/sqlite_diagnostics.h
@@ -11,9 +11,8 @@ namespace sql {
   class ErrorDelegate;
 }
 
-// The following five factories create the error handlers that we use when
+// The following four factories create the error handlers that we use when
 // issuing sqlite commands during normal browser operation.
-sql::ErrorDelegate* GetErrorHandlerForCookieDb();
 sql::ErrorDelegate* GetErrorHandlerForHistoryDb();
 sql::ErrorDelegate* GetErrorHandlerForThumbnailDb();
 sql::ErrorDelegate* GetErrorHandlerForTextDb();