Fix crash when querying a runtime config that is defined in environment

include/utils/SkRTConf.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 SkRTConf_DEFINED
 #define SkRTConf_DEFINED
@@ skipping 55 matching lines @@
 
 class SkRTConfRegistry {
 public:
     SkRTConfRegistry();
     void printAll(const char *fname = NULL) const;
     void printNonDefault(const char *fname = NULL) const;
     const char *configFileLocation() const;
     void possiblyDumpFile() const;
     void validate() const;
     template <typename T> void set(const char *confname, T value);
+#ifdef SK_SUPPORT_UNITTEST
+    static void UnitTest();
+#endif
 private:
     template<typename T> friend class SkRTConf;
 
     void registerConf(SkRTConfBase *conf);
     template <typename T> bool parse(const char *name, T* value);
 
     SkTDArray<SkString *> fConfigFileKeys, fConfigFileValues;
     typedef SkTDict< SkTDArray<SkRTConfBase *> * > ConfMap;
     ConfMap fConfs;
+#ifdef SK_SUPPORT_UNITTEST
+    SkRTConfRegistry(bool);
+#endif
 };
 
 // our singleton registry
 
 SkRTConfRegistry &skRTConfRegistry();
 
 template<typename T>
 SkRTConf<T>::SkRTConf(const char *name, const T &defaultValue, const char *description)
     : SkRTConfBase(name)
     , fValue(defaultValue)
@@ skipping 68 matching lines @@
     // static_cast here is okay because there's only one kind of child class.
     const SkRTConf<T> *child_pointer = static_cast<const SkRTConf<T> *>(conf);
     return child_pointer &&
            fName == child_pointer->fName &&
            fDescription == child_pointer->fDescription &&
            fValue == child_pointer->fValue &&
            fDefault == child_pointer->fDefault;
 }
 
 #endif