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

src/image/SkSurface_Gpu.cpp

 /*
  * Copyright 2012 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkSurface_Gpu.h"
 
 #include "SkCanvas.h"
@@ skipping 65 matching lines @@
                                       &this->props());
 }
 
 SkImage* SkSurface_Gpu::onNewImageSnapshot(Budgeted budgeted) {
     const SkImageInfo info = fDevice->imageInfo();
     const int sampleCount = fDevice->accessRenderTarget()->numColorSamples();
     SkImage* image = NULL;
     GrTexture* tex = fDevice->accessRenderTarget()->asTexture();
     if (tex) {
         image = SkNEW_ARGS(SkImage_Gpu,
-                           (info.width(), info.height(), info.alphaType(),
+                           (info.width(), info.height(), kNeedNewImageUniqueID, info.alphaType(),
                             tex, sampleCount, budgeted));
     }
     if (image) {
         as_IB(image)->initWithProps(this->props());
     }
     return image;
 }
 
 // Create a new render target and, if necessary, copy the contents of the old
 // render target into it. Note that this flushes the SkGpuDevice but
@@ skipping 70 matching lines @@
     }
     SkAutoTUnref<SkGpuDevice> device(SkGpuDevice::Create(rt, props,
                                                          SkGpuDevice::kUninit_InitContents));
     if (!device) {
         return NULL;
     }
     return SkNEW_ARGS(SkSurface_Gpu, (device));
 }
 
 #endif