More detailed implementation of the RequestPicker

components/offline_pages/background/device_conditions.h

 // Copyright 2016 The Chromium 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 COMPONENTS_OFFLINE_PAGES_BACKGROUND_DEVICE_CONDITIONS_H_
 #define COMPONENTS_OFFLINE_PAGES_BACKGROUND_DEVICE_CONDITIONS_H_
 
 #include "net/base/network_change_notifier.h"
 
 namespace offline_pages {
 
 // Device network and power conditions.
 class DeviceConditions {
  public:
   DeviceConditions(
       bool power_connected,
       int battery_percentage,
       net::NetworkChangeNotifier::ConnectionType net_connection_type)
       : power_connected_(power_connected),
         battery_percentage_(battery_percentage),
         net_connection_type_(net_connection_type) {}
 
+  DeviceConditions()

[dougarnett, 2016/07/18 21:45:44]

why would we want default ctor to have weakest set of constraints?

[Pete Williamson, 2016/07/18 22:52:09]

Ideally, the default ctor is only used when constraints are not available to the
code building it, and will be set later, so these values should never actually
be seen. 

However, if you prefer stronger constraints in case one slips through, let me
know what you prefer, and I'm happy to change the default ctor.

[dougarnett, 2016/07/19 00:20:44]

Indeed, since it is public it was a concern of default instance slipping through
by some maintenance developer down the road. 

I haven't noticed where it is needed/used yet. My first choice would be to see
if it could be protected or private. If not, the power connection true on
UNMETERED network would make me less twitchy here. 

[Pete Williamson, 2016/07/19 19:48:08]

Changed to power on, 75% battery, and unmetered network.

+      : power_connected_(false), battery_percentage_(0),
+        net_connection_type_(net::NetworkChangeNotifier::CONNECTION_NONE) {}
+
+  DeviceConditions(const DeviceConditions& other)
+      : power_connected_(other.power_connected_),
+      battery_percentage_(other.battery_percentage_),
+      net_connection_type_(other.net_connection_type_) {}
+
   // Returns whether power is connected.
   bool IsPowerConnected() const { return power_connected_; }
 
   // Returns percentage of remaining battery power (0-100).
   int GetBatteryPercentage() const { return battery_percentage_; }
 
   // Returns the current type of network connection, if any.
   net::NetworkChangeNotifier::ConnectionType GetNetConnectionType() const {
     return net_connection_type_;
   }
 
  private:
   const bool power_connected_;
   const int battery_percentage_;
   const net::NetworkChangeNotifier::ConnectionType net_connection_type_;
 };
 
 }  // namespace offline_pages
 
 #endif  // COMPONENTS_OFFLINE_PAGES_BACKGROUND_DEVICE_CONDITIONS_H_