Fixed a few places where uninitialized memory could have been read

src/core/SkValidatingReadBuffer.h

 /*
  * Copyright 2013 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef SkValidatingReadBuffer_DEFINED
 #define SkValidatingReadBuffer_DEFINED
 
@@ skipping 43 matching lines @@
     virtual bool readScalarArray(SkScalar* values, size_t size) SK_OVERRIDE;
 
     // helpers to get info about arrays and binary data
     virtual uint32_t getArrayCount() SK_OVERRIDE;
 
     virtual void readBitmap(SkBitmap* bitmap) SK_OVERRIDE;
     // TODO: Implement this (securely) when needed
     virtual SkTypeface* readTypeface() SK_OVERRIDE;
 
     virtual bool validate(bool isValid) SK_OVERRIDE;
+    virtual bool isValid() const SK_OVERRIDE;
 
 private:
     bool readArray(void* value, size_t size, size_t elementSize);
 
     void setMemory(const void* data, size_t size);
 
     static bool IsPtrAlign4(const void* ptr) {
         return SkIsAlign4((uintptr_t)ptr);
     }
 
     SkReader32 fReader;
     bool fError;
 
     typedef SkFlattenableReadBuffer INHERITED;
 };
 
 #endif // SkValidatingReadBuffer_DEFINED