diff -r 000000000000 -r 6474c204b198 dom/file/File.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/dom/file/File.cpp	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,78 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "File.h"
+
+#include "LockedFile.h"
+
+USING_FILE_NAMESPACE
+using mozilla::dom::indexedDB::IndexedDatabaseManager;
+
+// Create slice
+File::File(const File* aOther, uint64_t aStart, uint64_t aLength,
+           const nsAString& aContentType)
+: nsDOMFileCC(aContentType, aOther->mStart + aStart, aLength),
+  mFile(aOther->mFile), mLockedFile(aOther->mLockedFile),
+  mWholeFile(false), mStoredFile(aOther->mStoredFile)
+{
+  NS_ASSERTION(mFile, "Null file!");
+  NS_ASSERTION(mLockedFile, "Null locked file!");
+
+  if (mStoredFile) {
+    FileInfo* fileInfo;
+
+    if (IndexedDatabaseManager::IsClosed()) {
+      fileInfo = aOther->GetFileInfo();
+    }
+    else {
+      MutexAutoLock lock(IndexedDatabaseManager::FileMutex());
+      fileInfo = aOther->GetFileInfo();
+    }
+
+    mFileInfos.AppendElement(fileInfo);
+  }
+}
+
+NS_IMPL_CYCLE_COLLECTION_INHERITED(File, nsDOMFileCC,
+                                   mLockedFile)
+
+NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION_INHERITED(File)
+NS_INTERFACE_MAP_END_INHERITING(nsDOMFileCC)
+
+NS_IMPL_ADDREF_INHERITED(File, nsDOMFileCC)
+NS_IMPL_RELEASE_INHERITED(File, nsDOMFileCC)
+
+NS_IMETHODIMP
+File::GetInternalStream(nsIInputStream **aStream)
+{
+  NS_ASSERTION(NS_IsMainThread(), "Wrong thread!");
+
+  nsresult rv = mLockedFile->OpenInputStream(mWholeFile, mStart, mLength,
+                                             aStream);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  return NS_OK;
+}
+
+already_AddRefed<nsIDOMBlob>
+File::CreateSlice(uint64_t aStart, uint64_t aLength,
+                  const nsAString& aContentType)
+{
+  NS_ASSERTION(NS_IsMainThread(), "Wrong thread!");
+
+  nsCOMPtr<nsIDOMBlob> t =
+    new File(this, aStart, aLength, aContentType);
+  return t.forget();
+}
+
+NS_IMETHODIMP
+File::GetMozFullPathInternal(nsAString &aFilename)
+{
+  NS_ASSERTION(NS_IsMainThread(), "Wrong thread!");
+  NS_ASSERTION(mIsFile, "Should only be called on files");
+
+  return mFile->GetPath(aFilename);
+}