diff --git a/dom/devicestorage/nsDeviceStorage.cpp b/dom/devicestorage/nsDeviceStorage.cpp
index e2ca9778d9d8..e12665c9e446 100644
--- a/dom/devicestorage/nsDeviceStorage.cpp
+++ b/dom/devicestorage/nsDeviceStorage.cpp
@@ -851,44 +851,20 @@ NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END
 class PostErrorEvent : public nsRunnable
 {
 public:
-  PostErrorEvent(nsRefPtr<DOMRequest>& aRequest, const char* aMessage, DeviceStorageFile* aFile)
+  PostErrorEvent(nsRefPtr<DOMRequest>& aRequest, const char* aMessage)
   {
     mRequest.swap(aRequest);
-    BuildErrorString(aMessage, aFile);
+    CopyASCIItoUTF16(aMessage, mError);
   }
 
-  PostErrorEvent(DOMRequest* aRequest, const char* aMessage, DeviceStorageFile* aFile)
+  PostErrorEvent(DOMRequest* aRequest, const char* aMessage)
     : mRequest(aRequest)
   {
-    BuildErrorString(aMessage, aFile);
+    CopyASCIItoUTF16(aMessage, mError);
   }
 
   ~PostErrorEvent() {}
 
-  void BuildErrorString(const char* aMessage, DeviceStorageFile* aFile)
-  {
-    nsAutoString fullPath;
-
-    if (aFile && aFile->mFile) {
-      aFile->mFile->GetPath(fullPath);
-    }
-    else {
-      fullPath.Assign(NS_LITERAL_STRING("null file"));
-    }
-
-    mError = NS_ConvertASCIItoUTF16(aMessage);
-    mError.Append(NS_LITERAL_STRING(" file path = "));
-    mError.Append(fullPath.get());
-    mError.Append(NS_LITERAL_STRING(" path = "));
-
-    if (aFile) {
-      mError.Append(aFile->mPath);
-    }
-    else {
-      mError.Append(NS_LITERAL_STRING("null path"));
-    }
-  }
-
   NS_IMETHOD Run()
   {
     NS_ASSERTION(NS_IsMainThread(), "Wrong thread!");
@@ -1006,9 +982,7 @@ public:
     bool check;
     mFile->mFile->IsDirectory(&check);
     if (!check) {
-      nsCOMPtr<PostErrorEvent> event = new PostErrorEvent(mRequest,
-                                                          POST_ERROR_EVENT_FILE_NOT_ENUMERABLE,
-                                                          mFile);
+      nsCOMPtr<PostErrorEvent> event = new PostErrorEvent(mRequest, POST_ERROR_EVENT_FILE_NOT_ENUMERABLE);
       NS_DispatchToMainThread(event);
       return NS_OK;
     }
@@ -1093,9 +1067,7 @@ nsDOMDeviceStorageCursor::GetElement(nsIDOMElement * *aRequestingElement)
 NS_IMETHODIMP
 nsDOMDeviceStorageCursor::Cancel()
 {
-  nsCOMPtr<PostErrorEvent> event = new PostErrorEvent(this,
-                                                      POST_ERROR_EVENT_PERMISSION_DENIED,
-                                                      mFile);
+  nsCOMPtr<PostErrorEvent> event = new PostErrorEvent(this, POST_ERROR_EVENT_PERMISSION_DENIED);
   NS_DispatchToMainThread(event);
   return NS_OK;
 }
@@ -1104,9 +1076,7 @@ NS_IMETHODIMP
 nsDOMDeviceStorageCursor::Allow()
 {
   if (!mFile->IsSafePath()) {
-    nsCOMPtr<nsIRunnable> r = new PostErrorEvent(this,
-                                                 POST_ERROR_EVENT_ILLEGAL_FILE_NAME,
-                                                 mFile);
+    nsCOMPtr<nsIRunnable> r = new PostErrorEvent(this, POST_ERROR_EVENT_PERMISSION_DENIED);
     NS_DispatchToMainThread(r);
     return NS_OK;
   }
@@ -1288,9 +1258,7 @@ public:
     bool check = false;
     mFile->mFile->Exists(&check);
     if (check) {
-      nsCOMPtr<PostErrorEvent> event = new PostErrorEvent(mRequest,
-                                                          POST_ERROR_EVENT_FILE_EXISTS,
-                                                          mFile);
+      nsCOMPtr<PostErrorEvent> event = new PostErrorEvent(mRequest, POST_ERROR_EVENT_FILE_EXISTS);
       NS_DispatchToMainThread(event);
       return NS_OK;
     }
@@ -1300,9 +1268,7 @@ public:
     if (NS_FAILED(rv)) {
       mFile->mFile->Remove(false);
 
-      nsCOMPtr<PostErrorEvent> event = new PostErrorEvent(mRequest,
-                                                          POST_ERROR_EVENT_UNKNOWN,
-                                                          mFile);
+      nsCOMPtr<PostErrorEvent> event = new PostErrorEvent(mRequest, POST_ERROR_EVENT_UNKNOWN);
       NS_DispatchToMainThread(event);
       return NS_OK;
     }
@@ -1339,7 +1305,7 @@ public:
       bool check = false;
       mFile->mFile->Exists(&check);
       if (!check) {
-        r = new PostErrorEvent(mRequest, POST_ERROR_EVENT_FILE_DOES_NOT_EXIST, mFile);
+        r = new PostErrorEvent(mRequest, POST_ERROR_EVENT_FILE_DOES_NOT_EXIST);
       }
     }
 
@@ -1376,7 +1342,7 @@ public:
     bool check = false;
     mFile->mFile->Exists(&check);
     if (check) {
-      r = new PostErrorEvent(mRequest, POST_ERROR_EVENT_FILE_DOES_NOT_EXIST, mFile);
+      r = new PostErrorEvent(mRequest, POST_ERROR_EVENT_FILE_DOES_NOT_EXIST);
     }
     else {
       r = new PostResultEvent(mRequest, mFile->mPath);
@@ -1537,9 +1503,7 @@ public:
 
   NS_IMETHOD Cancel()
   {
-    nsCOMPtr<PostErrorEvent> event = new PostErrorEvent(mRequest,
-                                                        POST_ERROR_EVENT_PERMISSION_DENIED,
-                                                        mFile);
+    nsCOMPtr<PostErrorEvent> event = new PostErrorEvent(mRequest, POST_ERROR_EVENT_PERMISSION_DENIED);
     NS_DispatchToMainThread(event);
     return NS_OK;
   }
@@ -1849,10 +1813,10 @@ nsDOMDeviceStorage::AddNamed(nsIDOMBlob *aBlob,
   nsRefPtr<DeviceStorageFile> dsf = new DeviceStorageFile(mStorageType, mRootDirectory, aPath);
   if (!typeChecker->Check(mStorageType, dsf->mFile) ||
       !typeChecker->Check(mStorageType, aBlob)) {
-    r = new PostErrorEvent(request, POST_ERROR_EVENT_ILLEGAL_TYPE, dsf);
+    r = new PostErrorEvent(request, POST_ERROR_EVENT_ILLEGAL_TYPE);
   }
   else if (!dsf->IsSafePath()) {
-    r = new PostErrorEvent(request, POST_ERROR_EVENT_ILLEGAL_FILE_NAME, dsf);
+    r = new PostErrorEvent(request, POST_ERROR_EVENT_PERMISSION_DENIED);
   }
   else {
     r = new DeviceStorageRequest(DeviceStorageRequest::DEVICE_STORAGE_REQUEST_WRITE,
@@ -1898,10 +1862,7 @@ nsDOMDeviceStorage::GetInternal(const JS::Value & aPath,
   JSString* jsstr = JS_ValueToString(aCx, aPath);
   nsDependentJSString path;
   if (!path.init(aCx, jsstr)) {
-    nsRefPtr<DeviceStorageFile> dsf = new DeviceStorageFile(mStorageType, mRootDirectory);
-    r = new PostErrorEvent(request,
-                           POST_ERROR_EVENT_NON_STRING_TYPE_UNSUPPORTED,
-                           dsf);
+    r = new PostErrorEvent(request, POST_ERROR_EVENT_UNKNOWN);
     NS_DispatchToMainThread(r);
     return NS_OK;
   }
@@ -1909,7 +1870,7 @@ nsDOMDeviceStorage::GetInternal(const JS::Value & aPath,
   nsRefPtr<DeviceStorageFile> dsf = new DeviceStorageFile(mStorageType, mRootDirectory, path);
   dsf->SetEditable(aEditable);
   if (!dsf->IsSafePath()) {
-    r = new PostErrorEvent(request, POST_ERROR_EVENT_ILLEGAL_FILE_NAME, dsf);
+    r = new PostErrorEvent(request, POST_ERROR_EVENT_PERMISSION_DENIED);
   } else {
     r = new DeviceStorageRequest(DeviceStorageRequest::DEVICE_STORAGE_REQUEST_READ,
                                  win, mPrincipal, dsf, request);
@@ -1934,8 +1895,7 @@ nsDOMDeviceStorage::Delete(const JS::Value & aPath, JSContext* aCx, nsIDOMDOMReq
   JSString* jsstr = JS_ValueToString(aCx, aPath);
   nsDependentJSString path;
   if (!path.init(aCx, jsstr)) {
-    nsRefPtr<DeviceStorageFile> dsf = new DeviceStorageFile(mStorageType, mRootDirectory);
-    r = new PostErrorEvent(request, POST_ERROR_EVENT_NON_STRING_TYPE_UNSUPPORTED, dsf);
+    r = new PostErrorEvent(request, POST_ERROR_EVENT_UNKNOWN);
     NS_DispatchToMainThread(r);
     return NS_OK;
   }
@@ -1943,7 +1903,7 @@ nsDOMDeviceStorage::Delete(const JS::Value & aPath, JSContext* aCx, nsIDOMDOMReq
   nsRefPtr<DeviceStorageFile> dsf = new DeviceStorageFile(mStorageType, mRootDirectory, path);
 
   if (!dsf->IsSafePath()) {
-    r = new PostErrorEvent(request, POST_ERROR_EVENT_ILLEGAL_FILE_NAME, dsf);
+    r = new PostErrorEvent(request, POST_ERROR_EVENT_PERMISSION_DENIED);
   }
   else {
     r = new DeviceStorageRequest(DeviceStorageRequest::DEVICE_STORAGE_REQUEST_DELETE,
diff --git a/dom/devicestorage/nsDeviceStorage.h b/dom/devicestorage/nsDeviceStorage.h
index dfed1661e962..279c2977b0db 100644
--- a/dom/devicestorage/nsDeviceStorage.h
+++ b/dom/devicestorage/nsDeviceStorage.h
@@ -32,15 +32,12 @@ class nsPIDOMWindow;
 
 #include "DeviceStorageRequestChild.h"
 
-#define POST_ERROR_EVENT_FILE_EXISTS                 "File already exists"
-#define POST_ERROR_EVENT_FILE_DOES_NOT_EXIST         "File location doesn't exists"
-#define POST_ERROR_EVENT_FILE_NOT_ENUMERABLE         "File location is not enumerable"
-#define POST_ERROR_EVENT_PERMISSION_DENIED           "Permission Denied"
-#define POST_ERROR_EVENT_ILLEGAL_FILE_NAME           "Illegal file name"
-#define POST_ERROR_EVENT_ILLEGAL_TYPE                "Illegal content type"
+#define POST_ERROR_EVENT_FILE_EXISTS                 "NoModificationAllowedError"
+#define POST_ERROR_EVENT_FILE_DOES_NOT_EXIST         "NotFoundError"
+#define POST_ERROR_EVENT_FILE_NOT_ENUMERABLE         "TypeMismatchError"
+#define POST_ERROR_EVENT_PERMISSION_DENIED           "SecurityError"
+#define POST_ERROR_EVENT_ILLEGAL_TYPE                "TypeMismatchError"
 #define POST_ERROR_EVENT_UNKNOWN                     "Unknown"
-#define POST_ERROR_EVENT_NON_STRING_TYPE_UNSUPPORTED "Non-string type unsupported"
-#define POST_ERROR_EVENT_NOT_IMPLEMENTED             "Not implemented"
 
 using namespace mozilla;
 using namespace mozilla::dom;
diff --git a/dom/devicestorage/test/test_addCorrectType.html b/dom/devicestorage/test/test_addCorrectType.html
index 2920840f91ea..1a4cd8b3f483 100644
--- a/dom/devicestorage/test/test_addCorrectType.html
+++ b/dom/devicestorage/test/test_addCorrectType.html
@@ -43,6 +43,8 @@ var tests = [
 
 function fail(e) {
   ok(false, "addSuccess was called");
+  ok(e.target.error.name == "TypeMismatchError", "Error must be TypeMismatchError");
+
   devicestorage_cleanup();
 }
 
diff --git a/dom/devicestorage/test/test_basic.html b/dom/devicestorage/test/test_basic.html
index 23ce6c142407..28e453740bea 100644
--- a/dom/devicestorage/test/test_basic.html
+++ b/dom/devicestorage/test/test_basic.html
@@ -13,7 +13,7 @@ https://bugzilla.mozilla.org/show_bug.cgi?id=717103
 
 <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css" />
 </head>
-<body onunload="unload()">
+<body>
 <a target="_blank" href="https://bugzilla.mozilla.org/show_bug.cgi?id=717103">Mozilla Bug 717103</a>
 <p id="display"></p>
 <div id="content" style="display: none">
@@ -22,15 +22,6 @@ https://bugzilla.mozilla.org/show_bug.cgi?id=717103
 <pre id="test">
 <script class="testbody" type="text/javascript">
 
-function unload() {
-  delete gDataBlob;
-  gDataBlob = null;
-
-  delete gFileReader;
-  gFileReader = null;
-}
-
-
 devicestorage_setup();
 
 var gFileName = "devicestorage/hi.png";
diff --git a/dom/devicestorage/test/test_dotdot.html b/dom/devicestorage/test/test_dotdot.html
index 00eb111197f8..f3b14c7ad073 100644
--- a/dom/devicestorage/test/test_dotdot.html
+++ b/dom/devicestorage/test/test_dotdot.html
@@ -45,9 +45,11 @@ function fail(e) {
 
 function next(e) {
 
-  if (e != undefined)
-    ok(true, "addError was called");
-  
+  if (e != undefined) {
+    ok(true, "addError was called");  
+    ok(e.target.error.name == "SecurityError", "Error must be SecurityError");
+  }
+
   var f = tests.pop();
 
   if (f == undefined) {
diff --git a/dom/devicestorage/test/test_overwrite.html b/dom/devicestorage/test/test_overwrite.html
index 8869e0567910..e5dce30a4be5 100644
--- a/dom/devicestorage/test/test_overwrite.html
+++ b/dom/devicestorage/test/test_overwrite.html
@@ -44,6 +44,7 @@ function addOverwritingSuccess(e) {
 
 function addOverwritingError(e) {
   ok(true, "Adding to the same location should fail");
+  ok(e.target.error.name == "NoModificationAllowedError", "Error must be NoModificationAllowedError");
 
   var storage = navigator.getDeviceStorage("pictures");
   request = storage.delete(filename)