Make stencils be attachable to render targets created via SkSurface::MakeFromBackendTextureAsRender…

include/core/SkSurface.h

 /*
  * Copyright 2012 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef SkSurface_DEFINED
 #define SkSurface_DEFINED
 
@@ skipping 67 matching lines @@
      *  Return a new surface using the specified render target.
      */
     static sk_sp<SkSurface> MakeRenderTargetDirect(GrRenderTarget*,
                                                    const SkSurfaceProps* = nullptr);
 
     /**
      *  Used to wrap a pre-existing backend 3D API texture as a SkSurface. The kRenderTarget flag
      *  must be set on GrBackendTextureDesc for this to succeed. Skia will not assume ownership
      *  of the texture and the client must ensure the texture is valid for the lifetime of the
      *  SkSurface.
+     *
+     *  If the requested sample count is greater than 0, the contents of the surface are undefined.
      */
     static sk_sp<SkSurface> MakeFromBackendTexture(GrContext*, const GrBackendTextureDesc&,
                                                    const SkSurfaceProps*);
 
     /**
      *  Used to wrap a pre-existing 3D API rendering target as a SkSurface. Skia will not assume
      *  ownership of the render target and the client must ensure the render target is valid for the
      *  lifetime of the SkSurface.
      */
     static sk_sp<SkSurface> MakeFromBackendRenderTarget(GrContext*,
                                                         const GrBackendRenderTargetDesc&,
                                                         const SkSurfaceProps*);
 
     /**
      *  Used to wrap a pre-existing 3D API texture as a SkSurface. Skia will treat the texture as
      *  a rendering target only, but unlike NewFromBackendRenderTarget, Skia will manage and own
      *  the associated render target objects (but not the provided texture). The kRenderTarget flag
      *  must be set on GrBackendTextureDesc for this to succeed. Skia will not assume ownership
      *  of the texture and the client must ensure the texture is valid for the lifetime of the
      *  SkSurface.
+     *
+     *  If the requested sample count is greater than 0, the contents of the surface are undefined.
      */
     static sk_sp<SkSurface> MakeFromBackendTextureAsRenderTarget(
             GrContext*, const GrBackendTextureDesc&, const SkSurfaceProps*);
 
     /**
      *  Return a new surface whose contents will be drawn to an offscreen
      *  render target, allocated by the surface.
      */
     static sk_sp<SkSurface> MakeRenderTarget(
             GrContext*, SkBudgeted, const SkImageInfo&, int sampleCount, const SkSurfaceProps*);
@@ skipping 248 matching lines @@
 private:
     const SkSurfaceProps fProps;
     const int            fWidth;
     const int            fHeight;
     uint32_t             fGenerationID;
 
     typedef SkRefCnt INHERITED;
 };
 
 #endif