diff -r 000000000000 -r 6474c204b198 gfx/src/nsRenderingContext.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gfx/src/nsRenderingContext.h	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,149 @@
+/* -*- 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 NSRENDERINGCONTEXT__H__
+#define NSRENDERINGCONTEXT__H__
+
+#include <stdint.h>                     // for uint32_t
+#include <sys/types.h>                  // for int32_t
+#include "gfxContext.h"                 // for gfxContext
+#include "mozilla/Assertions.h"         // for MOZ_ASSERT_HELPER2
+#include "mozilla/gfx/2D.h"
+#include "mozilla/gfx/UserData.h"       // for UserData, UserDataKey
+#include "nsAutoPtr.h"                  // for nsRefPtr
+#include "nsBoundingMetrics.h"          // for nsBoundingMetrics
+#include "nsColor.h"                    // for nscolor
+#include "nsCoord.h"                    // for nscoord, NSToIntRound
+#include "nsDeviceContext.h"            // for nsDeviceContext
+#include "nsFontMetrics.h"              // for nsFontMetrics
+#include "nsISupports.h"                // for NS_INLINE_DECL_REFCOUNTING, etc
+#include "nsString.h"               // for nsString
+#include "nscore.h"                     // for char16_t
+
+class gfxASurface;
+class nsIntRegion;
+struct nsPoint;
+struct nsRect;
+
+typedef enum {
+    nsLineStyle_kNone   = 0,
+    nsLineStyle_kSolid  = 1,
+    nsLineStyle_kDashed = 2,
+    nsLineStyle_kDotted = 3
+} nsLineStyle;
+
+class nsRenderingContext MOZ_FINAL
+{
+    typedef mozilla::gfx::UserData UserData;
+    typedef mozilla::gfx::UserDataKey UserDataKey;
+    typedef mozilla::gfx::DrawTarget DrawTarget;
+
+public:
+    nsRenderingContext() : mP2A(0.) {}
+
+    NS_INLINE_DECL_REFCOUNTING(nsRenderingContext)
+
+    void Init(nsDeviceContext* aContext, gfxASurface* aThebesSurface);
+    void Init(nsDeviceContext* aContext, gfxContext* aThebesContext);
+    void Init(nsDeviceContext* aContext, DrawTarget* aDrawTarget);
+
+    // These accessors will never return null.
+    gfxContext *ThebesContext() { return mThebes; }
+    DrawTarget *GetDrawTarget() { return mThebes->GetDrawTarget(); }
+    nsDeviceContext *DeviceContext() { return mDeviceContext; }
+    int32_t AppUnitsPerDevPixel() { return NSToIntRound(mP2A); }
+
+    // Graphics state
+
+    void PushState(void);
+    void PopState(void);
+    void IntersectClip(const nsRect& aRect);
+    void SetClip(const nsIntRegion& aRegion);
+    void SetLineStyle(nsLineStyle aLineStyle);
+    void SetColor(nscolor aColor);
+    void Translate(const nsPoint& aPt);
+    void Scale(float aSx, float aSy);
+
+    class AutoPushTranslation {
+        nsRenderingContext* mCtx;
+    public:
+        AutoPushTranslation(nsRenderingContext* aCtx, const nsPoint& aPt)
+            : mCtx(aCtx) {
+            mCtx->PushState();
+            mCtx->Translate(aPt);
+        }
+        ~AutoPushTranslation() {
+            mCtx->PopState();
+        }
+    };
+
+    // Shapes
+
+    void DrawLine(const nsPoint& aStartPt, const nsPoint& aEndPt);
+    void DrawLine(nscoord aX0, nscoord aY0, nscoord aX1, nscoord aY1);
+    void DrawRect(const nsRect& aRect);
+    void DrawRect(nscoord aX, nscoord aY, nscoord aWidth, nscoord aHeight);
+    void DrawEllipse(nscoord aX, nscoord aY, nscoord aWidth, nscoord aHeight);
+
+    void FillRect(const nsRect& aRect);
+    void FillRect(nscoord aX, nscoord aY, nscoord aWidth, nscoord aHeight);
+    void FillPolygon(const nsPoint aPoints[], int32_t aNumPoints);
+
+    void FillEllipse(const nsRect& aRect);
+    void FillEllipse(nscoord aX, nscoord aY, nscoord aWidth, nscoord aHeight);
+
+    void InvertRect(const nsRect& aRect);
+
+    // Text
+
+    void SetFont(nsFontMetrics *aFontMetrics);
+    nsFontMetrics *FontMetrics() { return mFontMetrics; } // may be null
+
+    void SetTextRunRTL(bool aIsRTL);
+
+    nscoord GetWidth(char aC);
+    nscoord GetWidth(char16_t aC);
+    nscoord GetWidth(const nsString& aString);
+    nscoord GetWidth(const char* aString);
+    nscoord GetWidth(const char* aString, uint32_t aLength);
+    nscoord GetWidth(const char16_t *aString, uint32_t aLength);
+
+    nsBoundingMetrics GetBoundingMetrics(const char16_t *aString,
+                                         uint32_t aLength);
+
+    void DrawString(const nsString& aString, nscoord aX, nscoord aY);
+    void DrawString(const char *aString, uint32_t aLength,
+                    nscoord aX, nscoord aY);
+    void DrawString(const char16_t *aString, uint32_t aLength,
+                    nscoord aX, nscoord aY);
+
+    void AddUserData(UserDataKey *key, void *userData, void (*destroy)(void*)) {
+      mUserData.Add(key, userData, destroy);
+    }
+    void *GetUserData(UserDataKey *key) {
+      return mUserData.Get(key);
+    }
+    void *RemoveUserData(UserDataKey *key) {
+      return mUserData.Remove(key);
+    }
+
+private:
+    // Private destructor, to discourage deletion outside of Release():
+    ~nsRenderingContext()
+    {
+    }
+
+    int32_t GetMaxChunkLength();
+
+    nsRefPtr<gfxContext> mThebes;
+    nsRefPtr<nsDeviceContext> mDeviceContext;
+    nsRefPtr<nsFontMetrics> mFontMetrics;
+
+    double mP2A; // cached app units per device pixel value
+
+    UserData mUserData;
+};
+
+#endif  // NSRENDERINGCONTEXT__H__