diff -r 000000000000 -r 6474c204b198 gfx/thebes/gfxDWriteCommon.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gfx/thebes/gfxDWriteCommon.cpp	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,71 @@
+/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 4 -*-
+ * 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 "gfxDWriteCommon.h"
+
+IDWriteFontFileLoader* gfxDWriteFontFileLoader::mInstance = nullptr;
+
+HRESULT STDMETHODCALLTYPE
+gfxDWriteFontFileLoader::CreateStreamFromKey(const void *fontFileReferenceKey, 
+                                             UINT32 fontFileReferenceKeySize, 
+                                             IDWriteFontFileStream **fontFileStream)
+{
+    if (!fontFileReferenceKey || !fontFileStream) {
+        return E_POINTER;
+    }
+
+    *fontFileStream = 
+        new gfxDWriteFontFileStream(
+        static_cast<const ffReferenceKey*>(fontFileReferenceKey)->mArray);
+
+    if (!*fontFileStream) {
+        return E_OUTOFMEMORY;
+    }
+    (*fontFileStream)->AddRef();
+    return S_OK;
+}
+
+gfxDWriteFontFileStream::gfxDWriteFontFileStream(FallibleTArray<uint8_t> *aData)
+{
+    mData.SwapElements(*aData);
+}
+
+gfxDWriteFontFileStream::~gfxDWriteFontFileStream()
+{
+}
+
+HRESULT STDMETHODCALLTYPE
+gfxDWriteFontFileStream::GetFileSize(UINT64 *fileSize)
+{
+    *fileSize = mData.Length();
+    return S_OK;
+}
+
+HRESULT STDMETHODCALLTYPE
+gfxDWriteFontFileStream::GetLastWriteTime(UINT64 *lastWriteTime)
+{
+    return E_NOTIMPL;
+}
+
+HRESULT STDMETHODCALLTYPE
+gfxDWriteFontFileStream::ReadFileFragment(const void **fragmentStart,
+                                          UINT64 fileOffset,
+                                          UINT64 fragmentSize,
+                                          void **fragmentContext)
+{
+    // We are required to do bounds checking.
+    if (fileOffset + fragmentSize > (UINT64)mData.Length()) {
+        return E_FAIL;
+    }
+    // We should be alive for the duration of this.
+    *fragmentStart = &mData[fileOffset];
+    *fragmentContext = nullptr;
+    return S_OK;
+}
+
+void STDMETHODCALLTYPE
+gfxDWriteFontFileStream::ReleaseFileFragment(void *fragmentContext)
+{
+}