Service Worker: Improve some exception messages (Chromium).

content/common/service_worker/service_worker_types.h

Index: content/common/service_worker/service_worker_types.h
diff --git a/content/common/service_worker/service_worker_types.h b/content/common/service_worker/service_worker_types.h
index 96657505b1d777dc0e9fb43f7b4d8d28ab118d5a..2ee1aebcf2638bf47ba5c8d5c66f3b419e9e4e8a 100644
--- a/content/common/service_worker/service_worker_types.h
+++ b/content/common/service_worker/service_worker_types.h
@@ -32,6 +32,11 @@ static const int kDocumentMainThreadId = 0;
 // and embedded worker.
 static const int kInvalidServiceWorkerRequestId = -1;
 
+// Constants for error messages.
+extern const char kServiceWorkerRegisterErrorPrefix[];
+extern const char kServiceWorkerUnregisterErrorPrefix[];
+extern const char kServiceWorkerGetRegistrationErrorPrefix[];
+
 // Constants for invalid identifiers.
 static const int kInvalidServiceWorkerHandleId = -1;
 static const int kInvalidServiceWorkerRegistrationHandleId = -1;