Move prepareForExternalIO from GrRenderTarget to GrDrawContext

include/gpu/GrSurface.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 GrSurface_DEFINED
 #define GrSurface_DEFINED
@@ skipping 96 matching lines @@
                      GrPixelConfig config,
                      const void* buffer,
                      size_t rowBytes = 0,
                      uint32_t pixelOpsFlags = 0);
 
     /**
      * After this returns any pending writes to the surface will be issued to the backend 3D API.
      */
     void flushWrites();
 
-
-    /**
-     * After this returns any pending surface IO will be issued to the backend 3D API and
-     * if the surface has MSAA it will be resolved.
-     */
-    void prepareForExternalIO();
-
     /** Access methods that are only to be used within Skia code. */
     inline GrSurfacePriv surfacePriv();
     inline const GrSurfacePriv surfacePriv() const;
 
     typedef void* ReleaseCtx;
     typedef void (*ReleaseProc)(ReleaseCtx);
 
     void setRelease(ReleaseProc proc, ReleaseCtx ctx) {
         fReleaseProc = proc;
         fReleaseCtx = ctx;
@@ skipping 36 matching lines @@
         }
     }
 
     ReleaseProc fReleaseProc;
     ReleaseCtx  fReleaseCtx;
 
     typedef GrGpuResource INHERITED;
 };
 
 #endif