Propagate validation errors

include/core/SkPicture.h

 /*
  * Copyright 2007 The Android Open Source Project
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef SkPicture_DEFINED
 #define SkPicture_DEFINED
 
@@ skipping 229 matching lines @@
 
     static_assert(MIN_PICTURE_VERSION <= 45,
                   "Remove decoding of old SkTypeface::Style from SkFontDescriptor.cpp.");
 
     static_assert(MIN_PICTURE_VERSION <= 48,
                   "Remove legacy gradient deserialization code from SkGradientShader.cpp.");
 
     static bool IsValidPictInfo(const SkPictInfo& info);
     static sk_sp<SkPicture> Forwardport(const SkPictInfo&,
                                         const SkPictureData*,
-                                        const SkReadBuffer* buffer);
+                                        SkReadBuffer* buffer);
 
     SkPictInfo createHeader() const;
     SkPictureData* backport() const;
 
     mutable uint32_t fUniqueID;
 };
 
 #endif