Cashew: implement backend usage API

src/data_plan.h

 // Copyright (c) 2010 The Chromium OS Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef SRC_DATA_PLAN_H_
 #define SRC_DATA_PLAN_H_
 
 #include <map>
 #include <string>
 #include <vector>
 
 #include <base/basictypes.h>  // NOLINT
 #include <base/time.h>  // NOLINT
+#include <base/values.h>  // NOLINT
 #include <dbus-c++/dbus.h>  // NOLINT
 
 namespace cashew {
 
 class DataPlan;
 
 // byte count
 // TODO(vlaviano): this should be a uint64, but libcros/Chrome expects this
 typedef int64 Bytes;
 
@@ skipping 38 matching lines @@
 
     // get plan max bytes
     virtual Bytes GetDataBytesMax() const;
 
     // get plan used bytes
     virtual Bytes GetDataBytesUsed() const;
 
     // return a{sv} representation for D-Bus
     virtual DBusDataPlan ToDBusFormat() const;
 
+    // construct DataPlan from DictionaryValue
+    static DataPlan* FromDictionaryValue(const DictionaryValue *value);
+
+    // convert ISO8601 time value in UTC to base::Time
+    // returns true on success and false on failure
+    // |time_out| must not be NULL and is set on a successful return
+    static bool TimeFromISO8601UTC(const std::string& time_8601_utc,
+                                   base::Time *time_out);
+
   private:
     // human-readable plan name
     const std::string name_;
 
     // plan type
     const Type type_;
 
     // last update time (i.e., how fresh is plan data)
     base::Time update_time_;
 
     // plan start time
     const base::Time start_time_;
 
     // plan end time
     const base::Time end_time_;
 
     // max bytes available during plan period
     // irrelevant for plans of type kTypeUnlimited
     const Bytes data_bytes_max_;
 
     // bytes consumed so far during plan period
     Bytes data_bytes_used_;
 
-    // convert plan type enum value to string
-    const char* TypeToString(Type) const;
+    // convert plan type enum value to string formatted for libcros
+    const char* TypeToLibcrosString(Type type) const;
+
+    // convert string formatted for Cros Usage API to plan type enum value
+    // returns true on success and false on failure
+    // |type_out| must not be NULL and is set on a successful return
+    static bool CrosUsageStringToType(const std::string& type_string,
+                                      Type *type_out);
 
     DISALLOW_COPY_AND_ASSIGN(DataPlan);
 };
 
 }  // namespace cashew
 
 #endif  // SRC_DATA_PLAN_H_