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

src/image/SkImage_Gpu.h

Index: src/image/SkImage_Gpu.h
diff --git a/src/image/SkImage_Gpu.h b/src/image/SkImage_Gpu.h
index df26f82b74e2e9a8a1bc720ce198a2a828b6311c..4c7ebd6f7185aef5c4d36c5157ba18982c48943f 100644
--- a/src/image/SkImage_Gpu.h
+++ b/src/image/SkImage_Gpu.h
@@ -23,8 +23,8 @@ 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();