diff -r 000000000000 -r 6474c204b198 gfx/thebes/gfxQuartzNativeDrawing.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gfx/thebes/gfxQuartzNativeDrawing.h	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,77 @@
+/* -*- 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/. */
+
+#ifndef _GFXQUARTZNATIVEDRAWING_H_
+#define _GFXQUARTZNATIVEDRAWING_H_
+
+#include "mozilla/Attributes.h"
+
+#include "gfxContext.h"
+#include "gfxQuartzSurface.h"
+#include "mozilla/gfx/BorrowedContext.h"
+#include "nsAutoPtr.h"
+
+class gfxQuartzNativeDrawing {
+public:
+
+    /* Create native Quartz drawing for a rectangle bounded by
+     * nativeRect.
+     *
+     * Typical usage looks like:
+     *
+     *   gfxQuartzNativeDrawing nativeDraw(ctx, nativeRect);
+     *   CGContextRef cgContext = nativeDraw.BeginNativeDrawing();
+     *   if (!cgContext)
+     *     return NS_ERROR_FAILURE;
+     *
+     *     ... call Quartz operations on CGContextRef to draw to nativeRect ...
+     *
+     *   nativeDraw.EndNativeDrawing();
+     *
+     * aNativeRect is the size of the surface (in Quartz/Cocoa points) that
+     * will be created _if_ the gfxQuartzNativeDrawing decides to create a new
+     * surface and CGContext for its drawing operations, which it then
+     * composites into the target gfxContext.
+     *
+     * (Note that aNativeRect will be ignored if the gfxQuartzNativeDrawing
+     * uses the target gfxContext directly.)
+     *
+     * The optional aBackingScale parameter is a scaling factor that will be
+     * applied when creating and rendering into such a temporary surface.
+     */
+    gfxQuartzNativeDrawing(gfxContext *ctx,
+                           const gfxRect& aNativeRect,
+                           gfxFloat aBackingScale = 1.0f);
+
+    /* Returns a CGContextRef which may be used for native drawing.  This
+     * CGContextRef is valid until EndNativeDrawing is called; if it is used
+     * for drawing after that time, the result is undefined. */
+    CGContextRef BeginNativeDrawing();
+
+    /* Marks the end of native drawing */
+    void EndNativeDrawing();
+
+private:
+    // don't allow copying via construction or assignment
+    gfxQuartzNativeDrawing(const gfxQuartzNativeDrawing&) MOZ_DELETE;
+    const gfxQuartzNativeDrawing& operator=(const gfxQuartzNativeDrawing&) MOZ_DELETE;
+
+
+    // Final destination context
+    nsRefPtr<gfxContext> mContext;
+    mozilla::RefPtr<mozilla::gfx::DrawTarget> mDrawTarget;
+    mozilla::gfx::BorrowedCGContext mBorrowedContext;
+    // context that draws to mQuartzSurface; can be different from mContext
+    // if mContext is not drawing to Quartz
+    nsRefPtr<gfxContext> mSurfaceContext;
+    gfxRect mNativeRect;
+    gfxFloat mBackingScale;
+
+    // saved state
+    nsRefPtr<gfxQuartzSurface> mQuartzSurface;
+    CGContextRef mCGContext;
+};
+
+#endif