Revert of Delete SkImageDecoder

src/core/SkBigPicture.h

 /*
  * Copyright 2015 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef SkBigPicture_DEFINED
 #define SkBigPicture_DEFINED
 
 #include "SkOncePtr.h"
 #include "SkPicture.h"
-#include "SkRect.h"
 #include "SkTemplates.h"
 
 class SkBBoxHierarchy;
-class SkMatrix;
 class SkRecord;
 
 // An implementation of SkPicture supporting an arbitrary number of drawing commands.
 class SkBigPicture final : public SkPicture {
 public:
     // AccelData provides a base class for device-specific acceleration data.
     class AccelData : public SkRefCnt { };
 
     // An array of refcounted const SkPicture pointers.
     class SnapshotArray : ::SkNoncopyable {
@@ skipping 54 matching lines @@
     const SkRect                          fCullRect;
     const size_t                          fApproxBytesUsedBySubPictures;
     SkOncePtr<const Analysis>             fAnalysis;
     SkAutoTUnref<const SkRecord>          fRecord;
     SkAutoTDelete<const SnapshotArray>    fDrawablePicts;
     SkAutoTUnref<const SkBBoxHierarchy>   fBBH;
     SkAutoTUnref<const AccelData>         fAccelData;
 };
 
 #endif//SkBigPicture_DEFINED