skia: Add support for CHROMIUM_image backed textures.

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 144 matching lines @@
 
     ~GrSurface() override {
         // check that invokeReleaseProc has been called (if needed)
         SkASSERT(NULL == fReleaseProc);
     }
 
     GrSurfaceDesc fDesc;
 
     void onRelease() override;
     void onAbandon() override;
+    bool reuseable() const override;

[bsalomon, 2016/02/04 16:27:08]

I think this can be done without a new function. If we just don't add a scratch
key when the resource is created it won't be recycled for another purpose.

[erikchen, 2016/02/04 18:44:07]

You're right. Done.

 
 private:
     void invokeReleaseProc() {
         if (fReleaseProc) {
             fReleaseProc(fReleaseCtx);
             fReleaseProc = NULL;
         }
     }
 
     ReleaseProc fReleaseProc;
     ReleaseCtx  fReleaseCtx;
 
     typedef GrGpuResource INHERITED;
 };
 
 #endif