[CrOS Tether] Add tether network properties (battery percentage, carrier, and signal strength) to t…

chromeos/network/tether_constants.h

+// Copyright 2017 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 CHROMEOS_NETWORK_TETHER_CONSTANTS_H_
+#define CHROMEOS_NETWORK_TETHER_CONSTANTS_H_
+
+#include "chromeos/chromeos_export.h"
+
+namespace chromeos {
+
+// This file contains constants for Chrome OS tether networks which are used
+// wherever Shill constants are appropriate. Tether networks are a Chrome OS
+// concept which does not exist as part of Shill, so these custom definitions
+// are used instead. Tether networks are never intended to be passed to Shill
+// code, and these values are used primarily to implement the

[stevenjb, 2017/04/14 22:04:49]

The real reason we uses these is that NetworkStateHandler deals with Shill
dictionaries, and the tether component interacts with NetworkStateHandler since
that is the class that maintains network state for all of Chrome OS.

Thinking about this though, there is no particular reason why NetworkState can't
just use the ONC constants. That would make it a little more clear that Tether
networks are not part of Shill.

If we do that, it may still make sense to provide a translation table in the ONC
code, just with a comment that the properties are coming from NSH and still need
to be validated.

(Sorry this did not occur to me sooner).

LMKWYT

[Kyle Horimoto, 2017/04/17 21:05:11]

While this solution could also work, Ryan and I agreed that it is easier to
understand by using fill-in Shill types. Using this strategy treats all
Shill/ONC conversions the same way, and it also uses the same style of
constants. Shill constants all use the same property naming scheme:
"<NetworkType>.<PropertyName>", so we think it makes more sense to treat tether
networks the same way. This also is consistent with the JSON-ified Shill
networks in 	chromeos/test/data/network.

+// chrome.networkingPrivate API.
+
+// Represents the tether network type.
+CHROMEOS_EXPORT extern const char kTypeTether[];
+
+// Properties associated with tether networks.
+CHROMEOS_EXPORT extern const char kTetherBatteryPercentage[];
+CHROMEOS_EXPORT extern const char kTetherCarrier[];
+CHROMEOS_EXPORT extern const char kTetherSignalStrength[];
+
+}  // namespace chromeos
+
+#endif  // CHROMEOS_NETWORK_TETHER_CONSTANTS_H_