Revert of Sketch splitting SkPicture into an interface and SkBigPicture.

src/gpu/SkGpuDevice.cpp

 /*
  * Copyright 2011 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkGpuDevice.h"
 
 #include "GrContext.h"
@@ skipping 1996 matching lines @@
 }
 
 bool SkGpuDevice::EXPERIMENTAL_drawPicture(SkCanvas* mainCanvas, const SkPicture* mainPicture,
                                            const SkMatrix* matrix, const SkPaint* paint) {
 #ifndef SK_IGNORE_GPU_LAYER_HOISTING
     // todo: should handle this natively
     if (paint) {
         return false;
     }
 
-    const SkBigPicture::AccelData* data = NULL;
-    if (const SkBigPicture* bp = mainPicture->asSkBigPicture()) {
-        data = bp->accelData();
-    }
+    SkPicture::AccelData::Key key = SkLayerInfo::ComputeKey();
+
+    const SkPicture::AccelData* data = mainPicture->EXPERIMENTAL_getAccelData(key);
     if (!data) {
         return false;
     }
 
     const SkLayerInfo *gpuData = static_cast<const SkLayerInfo*>(data);
     if (0 == gpuData->numBlocks()) {
         return false;
     }
 
     SkTDArray<GrHoistedLayer> atlasedNeedRendering, atlasedRecycled;
@@ skipping 42 matching lines @@
 #endif
 }
 
 SkImageFilter::Cache* SkGpuDevice::getImageFilterCache() {
     // We always return a transient cache, so it is freed after each
     // filter traversal.
     return SkImageFilter::Cache::Create(kDefaultImageFilterCacheSize);
 }
 
 #endif