Cleanup SkPicture* classes a bit

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 "effects/GrBicubicEffect.h"
@@ skipping 1822 matching lines @@
     result->setInfo(info);
     result->setPixelRef(SkNEW_ARGS(SkGrPixelRef, (info, texture)))->unref();
 }
 
 void SkGpuDevice::EXPERIMENTAL_purge(const SkPicture* picture) {
     fContext->getLayerCache()->purge(picture);
 }
 
 bool SkGpuDevice::EXPERIMENTAL_drawPicture(SkCanvas* canvas, const SkPicture* picture) {
 
-    if (NULL == picture->fData.get()) {
-        return false;
-    }
-
     SkPicture::AccelData::Key key = GPUAccelData::ComputeAccelDataKey();
 
     const SkPicture::AccelData* data = picture->EXPERIMENTAL_getAccelData(key);
     if (NULL == data) {
         return false;
     }
 
     const GPUAccelData *gpuData = static_cast<const GPUAccelData*>(data);
 
     if (0 == gpuData->numSaveLayers()) {
@@ skipping 178 matching lines @@
     playback.draw(canvas, NULL);
 
     // unlock the layers
     for (int i = 0; i < gpuData->numSaveLayers(); ++i) {
         GrCachedLayer* layer = fContext->getLayerCache()->findLayer(picture, i);
         fContext->getLayerCache()->unlock(layer);
     }
 
     return true;
 }