Drawstate on stack

src/gpu/GrGpu.h

 /*
  * Copyright 2011 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef GrGpu_DEFINED
 #define GrGpu_DEFINED
 
@@ skipping 342 matching lines @@
      * is called.
      */
     void saveActiveTraceMarkers();
     void restoreActiveTraceMarkers();
 
     // Called to determine whether an onCopySurface call would succeed or not. This is useful for
     // proxy subclasses to test whether the copy would succeed without executing it yet. Derived
     // classes must keep this consistent with their implementation of onCopySurface(). The inputs
     // are the same as onCopySurface(), i.e. srcRect and dstPoint are clipped to be inside the src
     // and dst bounds.
-    virtual bool canCopySurface(GrSurface* dst,
-                                GrSurface* src,
+    virtual bool canCopySurface(const GrSurface* dst,
+                                const GrSurface* src,
                                 const SkIRect& srcRect,
                                 const SkIPoint& dstPoint) = 0;
 
     // This method is called by copySurface  The srcRect is guaranteed to be entirely within the
     // src bounds. Likewise, the dst rect implied by dstPoint and srcRect's width and height falls
     // entirely within the dst. The default implementation will draw a rect from the src to the
     // dst if the src is a texture and the dst is a render target and fail otherwise.
     virtual bool copySurface(GrSurface* dst,
                              GrSurface* src,
                              const SkIRect& srcRect,
@@ skipping 188 matching lines @@
     int                                                                 fGpuTraceMarkerCount;
     GrTraceMarkerSet                                                    fActiveTraceMarkers;
     GrTraceMarkerSet                                                    fStoredTraceMarkers;
     // The context owns us, not vice-versa, so this ptr is not ref'ed by Gpu.
     GrContext*                                                          fContext;
 
     typedef SkRefCnt INHERITED;
 };
 
 #endif