diff -r 000000000000 -r 6474c204b198 gfx/gl/GLBlitTextureImageHelper.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gfx/gl/GLBlitTextureImageHelper.h	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,69 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/* vim: set ts=8 sts=4 et sw=4 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/. */
+
+#ifndef GLBLITTEXTUREIMAGEHELPER_H_
+#define GLBLITTEXTUREIMAGEHELPER_H_
+
+#include "mozilla/Attributes.h"
+#include "GLContextTypes.h"
+#include "GLConsts.h"
+
+struct nsIntRect;
+
+namespace mozilla {
+namespace gl {
+
+class GLContext;
+class TextureImage;
+
+class GLBlitTextureImageHelper MOZ_FINAL
+{
+    // The GLContext is the sole owner of the GLBlitTextureImageHelper.
+    GLContext* mGL;
+
+    // lazy-initialized things
+    GLuint mBlitProgram, mBlitFramebuffer;
+    void UseBlitProgram();
+    void SetBlitFramebufferForDestTexture(GLuint aTexture);
+
+public:
+
+    GLBlitTextureImageHelper(GLContext *gl);
+    ~GLBlitTextureImageHelper();
+
+    /**
+     * Copy a rectangle from one TextureImage into another.  The
+     * source and destination are given in integer coordinates, and
+     * will be converted to texture coordinates.
+     *
+     * For the source texture, the wrap modes DO apply -- it's valid
+     * to use REPEAT or PAD and expect appropriate behaviour if the source
+     * rectangle extends beyond its bounds.
+     *
+     * For the destination texture, the wrap modes DO NOT apply -- the
+     * destination will be clipped by the bounds of the texture.
+     *
+     * Note: calling this function will cause the following OpenGL state
+     * to be changed:
+     *
+     *   - current program
+     *   - framebuffer binding
+     *   - viewport
+     *   - blend state (will be enabled at end)
+     *   - scissor state (will be enabled at end)
+     *   - vertex attrib 0 and 1 (pointer and enable state [enable state will be disabled at exit])
+     *   - array buffer binding (will be 0)
+     *   - active texture (will be 0)
+     *   - texture 0 binding
+     */
+    void BlitTextureImage(TextureImage *aSrc, const nsIntRect& aSrcRect,
+                          TextureImage *aDst, const nsIntRect& aDstRect);
+};
+
+}
+}
+
+#endif // GLBLITTEXTUREIMAGEHELPER_H_