Sketch splitting SkPicture into an interface and SkBigPicture.

src/gpu/SkGpuDevice.cpp

Index: src/gpu/SkGpuDevice.cpp
diff --git a/src/gpu/SkGpuDevice.cpp b/src/gpu/SkGpuDevice.cpp
index 13b00defe45e2f038b9b8165db4f13fe97b0cf6f..d1d9d9ee882a534ceab54e52c3aa6ad1bf21d7e5 100644
--- a/src/gpu/SkGpuDevice.cpp
+++ b/src/gpu/SkGpuDevice.cpp
@@ -1985,9 +1985,10 @@ bool SkGpuDevice::EXPERIMENTAL_drawPicture(SkCanvas* mainCanvas, const SkPicture
         return false;
     }
 
-    SkPicture::AccelData::Key key = SkLayerInfo::ComputeKey();
-
-    const SkPicture::AccelData* data = mainPicture->EXPERIMENTAL_getAccelData(key);
+    const SkBigPicture::AccelData* data = NULL;
+    if (const SkBigPicture* bp = mainPicture->asSkBigPicture()) {
+        data = bp->accelData();
+    }
     if (!data) {
         return false;
     }