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diff --git a/gfx/layers/opengl/GLBlitTextureImageHelper.h b/gfx/layers/opengl/GLBlitTextureImageHelper.h
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+++ b/gfx/layers/opengl/GLBlitTextureImageHelper.h
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+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=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/. */
+
+#ifndef GLBLITTEXTUREIMAGEHELPER_H_
+#define GLBLITTEXTUREIMAGEHELPER_H_
+
+#include "mozilla/Attributes.h"
+#include "GLContextTypes.h"
+#include "GLConsts.h"
+#include "mozilla/gfx/Rect.h"
+
+namespace mozilla {
+namespace gl {
+class GLContext;
+class TextureImage;
+}  // namespace gl
+namespace layers {
+
+class CompositorOGL;
+
+class GLBlitTextureImageHelper final {
+  // The GLContext is the sole owner of the GLBlitTextureImageHelper.
+  CompositorOGL* mCompositor;
+
+  // lazy-initialized things
+  GLuint mBlitProgram, mBlitFramebuffer;
+  void UseBlitProgram();
+  void SetBlitFramebufferForDestTexture(GLuint aTexture);
+
+ public:
+  explicit GLBlitTextureImageHelper(CompositorOGL* 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(gl::TextureImage* aSrc, const gfx::IntRect& aSrcRect,
+                        gl::TextureImage* aDst, const gfx::IntRect& aDstRect);
+};
+
+}  // namespace layers
+}  // namespace mozilla
+
+#endif  // GLBLITTEXTUREIMAGEHELPER_H_