unify pixelref and image ID space, so we can share IDs when we share pixels

src/image/SkImage_Gpu.h

 /*
  * Copyright 2015 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef SkImage_Gpu_DEFINED
 #define SkImage_Gpu_DEFINED
 
 #include "GrTexture.h"
 #include "GrGpuResourcePriv.h"
 #include "SkBitmap.h"
 #include "SkImage_Base.h"
 #include "SkImagePriv.h"
 #include "SkSurface.h"
 
 class SkImage_Gpu : public SkImage_Base {
 public:
     
 
     /**
      *  An "image" can be a subset/window into a larger texture, so we explicit take the
      *  width and height.
      */
-    SkImage_Gpu(int w, int h, SkAlphaType, GrTexture*, int sampleCountForNewSurfaces,
-                SkSurface::Budgeted);
+    SkImage_Gpu(int w, int h, uint32_t uniqueID, SkAlphaType, GrTexture*,
+                int sampleCountForNewSurfaces, SkSurface::Budgeted);
 
     void applyBudgetDecision() const {
         GrTexture* tex = this->getTexture();
         SkASSERT(tex);
         if (fBudgeted) {
             tex->resourcePriv().makeBudgeted();
         } else {
             tex->resourcePriv().makeUnbudgeted();
         }
     }
@@ skipping 11 matching lines @@
 private:
     SkAutoTUnref<GrTexture> fTexture;
     const int               fSampleCountForNewSurfaces;   // 0 if we don't know
     const SkAlphaType       fAlphaType;
     SkSurface::Budgeted     fBudgeted;
 
     typedef SkImage_Base INHERITED;
 };
 
 #endif