Initial error handling code

include/effects/SkOffsetImageFilter.h

 /*
  * Copyright 2012 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 SkOffsetImageFilter_DEFINED
 #define SkOffsetImageFilter_DEFINED
 
 #include "SkImageFilter.h"
 #include "SkPoint.h"
 
 class SK_API SkOffsetImageFilter : public SkImageFilter {
+    typedef SkImageFilter INHERITED;
+
 public:
     SkOffsetImageFilter(SkScalar dx, SkScalar dy, SkImageFilter* input = NULL);
     SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkOffsetImageFilter)
 
 protected:
     SkOffsetImageFilter(SkFlattenableReadBuffer& buffer);
     virtual void flatten(SkFlattenableWriteBuffer&) const SK_OVERRIDE;
 
     virtual bool onFilterImage(Proxy*, const SkBitmap& src, const SkMatrix&,
                                SkBitmap* result, SkIPoint* loc) SK_OVERRIDE;
     virtual bool onFilterBounds(const SkIRect&, const SkMatrix&, SkIRect*) SK_OVERRIDE;
 
 private:
     SkVector fOffset;
-
-    typedef SkImageFilter INHERITED;
 };
 
 #endif