diff -r 000000000000 -r 6474c204b198 content/canvas/public/nsICanvasRenderingContextInternal.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/content/canvas/public/nsICanvasRenderingContextInternal.h	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,138 @@
+/* -*- Mode: C++; tab-width: 40; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* 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 nsICanvasRenderingContextInternal_h___
+#define nsICanvasRenderingContextInternal_h___
+
+#include "mozilla/gfx/2D.h"
+#include "nsISupports.h"
+#include "nsIInputStream.h"
+#include "nsIDocShell.h"
+#include "mozilla/dom/HTMLCanvasElement.h"
+#include "GraphicsFilter.h"
+#include "mozilla/RefPtr.h"
+
+#define NS_ICANVASRENDERINGCONTEXTINTERNAL_IID \
+{ 0x3cc9e801, 0x1806, 0x4ff6, \
+  { 0x86, 0x14, 0xf9, 0xd0, 0xf4, 0xfb, 0x3b, 0x08 } }
+
+class gfxContext;
+class gfxASurface;
+class nsDisplayListBuilder;
+
+namespace mozilla {
+namespace layers {
+class CanvasLayer;
+class LayerManager;
+}
+namespace ipc {
+class Shmem;
+}
+namespace gfx {
+class SourceSurface;
+}
+}
+
+class nsICanvasRenderingContextInternal : public nsISupports {
+public:
+  typedef mozilla::layers::CanvasLayer CanvasLayer;
+  typedef mozilla::layers::LayerManager LayerManager;
+
+  NS_DECLARE_STATIC_IID_ACCESSOR(NS_ICANVASRENDERINGCONTEXTINTERNAL_IID)
+
+  void SetCanvasElement(mozilla::dom::HTMLCanvasElement* aParentCanvas)
+  {
+    mCanvasElement = aParentCanvas;
+  }
+  mozilla::dom::HTMLCanvasElement* GetParentObject() const
+  {
+    return mCanvasElement;
+  }
+
+#ifdef DEBUG
+    // Useful for testing
+    virtual int32_t GetWidth() const = 0;
+    virtual int32_t GetHeight() const = 0;
+#endif
+
+  // Sets the dimensions of the canvas, in pixels.  Called
+  // whenever the size of the element changes.
+  NS_IMETHOD SetDimensions(int32_t width, int32_t height) = 0;
+
+  NS_IMETHOD InitializeWithSurface(nsIDocShell *docShell, gfxASurface *surface, int32_t width, int32_t height) = 0;
+
+  // Creates an image buffer. Returns null on failure.
+  virtual void GetImageBuffer(uint8_t** aImageBuffer, int32_t* aFormat) = 0;
+
+  // Gives you a stream containing the image represented by this context.
+  // The format is given in aMimeTime, for example "image/png".
+  //
+  // If the image format does not support transparency or aIncludeTransparency
+  // is false, alpha will be discarded and the result will be the image
+  // composited on black.
+  NS_IMETHOD GetInputStream(const char *aMimeType,
+                            const char16_t *aEncoderOptions,
+                            nsIInputStream **aStream) = 0;
+  
+  // This gets an Azure SourceSurface for the canvas, this will be a snapshot
+  // of the canvas at the time it was called.
+  // If aPremultAlpha is provided, then it assumed the callee can handle
+  // un-premultiplied surfaces, and *aPremultAlpha will be set to false
+  // if one is returned.
+  virtual mozilla::TemporaryRef<mozilla::gfx::SourceSurface> GetSurfaceSnapshot(bool* aPremultAlpha = nullptr) = 0;
+
+  // If this context is opaque, the backing store of the canvas should
+  // be created as opaque; all compositing operators should assume the
+  // dst alpha is always 1.0.  If this is never called, the context
+  // defaults to false (not opaque).
+  NS_IMETHOD SetIsOpaque(bool isOpaque) = 0;
+  virtual bool GetIsOpaque() = 0;
+
+  // Invalidate this context and release any held resources, in preperation
+  // for possibly reinitializing with SetDimensions/InitializeWithSurface.
+  NS_IMETHOD Reset() = 0;
+
+  // Return the CanvasLayer for this context, creating
+  // one for the given layer manager if not available.
+  virtual already_AddRefed<CanvasLayer> GetCanvasLayer(nsDisplayListBuilder* aBuilder,
+                                                       CanvasLayer *aOldLayer,
+                                                       LayerManager *aManager) = 0;
+
+  // Return true if the canvas should be forced to be "inactive" to ensure
+  // it can be drawn to the screen even if it's too large to be blitted by
+  // an accelerated CanvasLayer.
+  virtual bool ShouldForceInactiveLayer(LayerManager *aManager) { return false; }
+
+  virtual void MarkContextClean() = 0;
+
+  // Redraw the dirty rectangle of this canvas.
+  NS_IMETHOD Redraw(const gfxRect &dirty) = 0;
+
+  NS_IMETHOD SetContextOptions(JSContext* aCx, JS::Handle<JS::Value> aOptions) { return NS_OK; }
+
+  //
+  // shmem support
+  //
+
+  // If this context can be set to use Mozilla's Shmem segments as its backing
+  // store, this will set it to that state. Note that if you have drawn
+  // anything into this canvas before changing the shmem state, it will be
+  // lost.
+  NS_IMETHOD SetIsIPC(bool isIPC) = 0;
+
+protected:
+  nsRefPtr<mozilla::dom::HTMLCanvasElement> mCanvasElement;
+};
+
+namespace mozilla {
+namespace dom {
+
+}
+}
+
+NS_DEFINE_STATIC_IID_ACCESSOR(nsICanvasRenderingContextInternal,
+                              NS_ICANVASRENDERINGCONTEXTINTERNAL_IID)
+
+#endif /* nsICanvasRenderingContextInternal_h___ */