50 template <typename T>
51 class PollCopyVariable : public Variable<T> {
59                    const T& ref,  in PollCopyVariable()
62       : Variable<T>(name, kVariableModePoll),  in PollCopyVariable()
66   PollCopyVariable(const std::string& name, const T& ref, const bool* is_set_p)  in PollCopyVariable()
68   PollCopyVariable(const std::string& name, const T& ref)  in PollCopyVariable()
73                    const T& ref,  in PollCopyVariable()
76       : Variable<T>(name, poll_interval),  in PollCopyVariable()
82                    const T& ref,  in PollCopyVariable()
87                    const T& ref)  in PollCopyVariable()
95   inline const T* GetValue(base::TimeDelta /* timeout */,  in GetValue()
106     return new T(ref_);  in GetValue()
111   const T& ref_;
123 template <typename T>
124 class ConstCopyVariable : public Variable<T> {
129   ConstCopyVariable(const std::string& name, const T& obj)  in ConstCopyVariable()
130       : Variable<T>(name, kVariableModeConst), obj_(obj) {}  in ConstCopyVariable()
134   const T* GetValue(base::TimeDelta /* timeout */,  in GetValue()
136     return new T(obj_);  in GetValue()
141   const T obj_;
146 template <typename T>
147 class CallCopyVariable : public Variable<T> {
149   CallCopyVariable(const std::string& name, base::Callback<T(void)> func)  in CallCopyVariable()
150       : Variable<T>(name, kVariableModePoll), func_(func) {}  in CallCopyVariable()
153                    base::Callback<T(void)> func)  in CallCopyVariable()
154       : Variable<T>(name, poll_interval), func_(func) {}  in CallCopyVariable()
158   const T* GetValue(base::TimeDelta /* timeout */,  in GetValue()
162     return new T(func_.Run());  in GetValue()
169   base::Callback<T(void)> func_;
181 template <typename T>
182 class AsyncCopyVariable : public Variable<T> {
185       : Variable<T>(name, kVariableModeAsync), has_value_(false) {}  in AsyncCopyVariable()
187   AsyncCopyVariable(const std::string& name, const T value)  in AsyncCopyVariable()
188       : Variable<T>(name, kVariableModeAsync),  in AsyncCopyVariable()
192   void SetValue(const T& new_value) {  in SetValue()
209   const T* GetValue(base::TimeDelta /* timeout */,  in GetValue()
216     return new T(value_);  in GetValue()
224   T value_;