Expose cellular signal strength on Android to native

net/android/cellular_signal_strength_unittest.cc

+// 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.
+
+#include "net/android/cellular_signal_strength.h"
+
+#include <stdint.h>
+
+#include "net/base/network_change_notifier.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace net {
+
+namespace {
+
+TEST(CellularSignalStrengthAndroidTest, SignalStrengthTest) {
+  int signal_strength_dbm = CellularSignalStrengthError.ERROR_NOT_SUPPORTED;
+  bool signal_strength_available =
+      android::cellular_signal_strength::GetSignalStrengthDbm(
+          &signal_strength_dbm);
+
+  // Signal strength is likely unavailable if the device does not have an
+  // active cellular connection.
+  if (!NetworkChangeNotifier::IsConnectionCellular(
+          NetworkChangeNotifier::GetConnectionType())) {
+    return;
+  }
+
+  EXPECT_TRUE(signal_strength_available);
+  // Signal strength (in dbM) should typically be between -130 and 0.
+  EXPECT_LE(-130, signal_strength_dbm);
+  EXPECT_GE(0, signal_strength_dbm);
+}
+
+TEST(CellularSignalStrengthAndroidTest, SignalStrengthLevelTest) {
+  int signal_strength_level = CellularSignalStrengthError.ERROR_NOT_SUPPORTED;
+  bool signal_strength_level_available =
+      android::cellular_signal_strength::GetSignalLevel(&signal_strength_level);
+
+  // Signal strength is likely unavailable if the device does not have an

[bengr, 2016/06/27 01:36:22]

Why "likely?" Is the statement true if you remove the work "likely?"

[tbansal1, 2016/06/27 19:01:17]

I removed it. I am not sure what is the documented behavior of Android when the
data connection is not active.

+  // active cellular connection.
+  if (!NetworkChangeNotifier::IsConnectionCellular(
+          NetworkChangeNotifier::GetConnectionType())) {
+    return;
+  }
+
+  EXPECT_TRUE(signal_strength_level_available);
+  EXPECT_LE(0, signal_strength_level);
+  EXPECT_GE(4, signal_strength_level);
+}
+
+}  // namespace
+
+}  // namespace net