diff -r 000000000000 -r 6474c204b198 gfx/thebes/gfxAlphaRecovery.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gfx/thebes/gfxAlphaRecovery.cpp	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,53 @@
+/* -*- 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 "gfxAlphaRecovery.h"
+
+#include "gfxImageSurface.h"
+
+#define MOZILLA_SSE_INCLUDE_HEADER_FOR_SSE2
+#include "mozilla/SSE.h"
+
+/* static */ bool
+gfxAlphaRecovery::RecoverAlpha(gfxImageSurface* blackSurf,
+                               const gfxImageSurface* whiteSurf)
+{
+    gfxIntSize size = blackSurf->GetSize();
+
+    if (size != whiteSurf->GetSize() ||
+        (blackSurf->Format() != gfxImageFormat::ARGB32 &&
+         blackSurf->Format() != gfxImageFormat::RGB24) ||
+        (whiteSurf->Format() != gfxImageFormat::ARGB32 &&
+         whiteSurf->Format() != gfxImageFormat::RGB24))
+        return false;
+
+#ifdef MOZILLA_MAY_SUPPORT_SSE2
+    if (mozilla::supports_sse2() &&
+        RecoverAlphaSSE2(blackSurf, whiteSurf)) {
+        return true;
+    }
+#endif
+
+    blackSurf->Flush();
+    whiteSurf->Flush();
+
+    unsigned char* blackData = blackSurf->Data();
+    unsigned char* whiteData = whiteSurf->Data();
+
+    for (int32_t i = 0; i < size.height; ++i) {
+        uint32_t* blackPixel = reinterpret_cast<uint32_t*>(blackData);
+        const uint32_t* whitePixel = reinterpret_cast<uint32_t*>(whiteData);
+        for (int32_t j = 0; j < size.width; ++j) {
+            uint32_t recovered = RecoverPixel(blackPixel[j], whitePixel[j]);
+            blackPixel[j] = recovered;
+        }
+        blackData += blackSurf->Stride();
+        whiteData += whiteSurf->Stride();
+    }
+
+    blackSurf->MarkDirty();
+
+    return true;
+}