Add an Error class for ServiceWorkers

Source/modules/serviceworkers/ServiceWorkerError.cpp

Index: Source/modules/serviceworkers/ServiceWorkerError.cpp
diff --git a/Source/platform/audio/AudioDSPKernel.cpp b/Source/modules/serviceworkers/ServiceWorkerError.cpp
similarity index 83%
copy from Source/platform/audio/AudioDSPKernel.cpp
copy to Source/modules/serviceworkers/ServiceWorkerError.cpp
index 553ac05737a7b7e6631d9ea9ff3a2f2f5392e115..61572c6ec3fa11be01455a6d57e40b785b0a1b97 100644
--- a/Source/platform/audio/AudioDSPKernel.cpp
+++ b/Source/modules/serviceworkers/ServiceWorkerError.cpp
@@ -29,12 +29,20 @@
  */
 
 #include "config.h"
-#include "platform/audio/AudioDSPKernel.h"
+#include "ServiceWorkerError.h"
 
+using WebKit::WebServiceWorkerError;
 namespace WebCore {
 
-AudioDSPKernel::~AudioDSPKernel()
+String ServiceWorkerError::errorString(WebServiceWorkerError::ErrorType type)
 {
+    switch (type) {
+    case WebServiceWorkerError::DisabledError:
+        return "DisabledError";
+    default:
+        ASSERT_NOT_REACHED();
+    }
+    return String();
 }
 
 }