[NetworkChangeNotifier] Run Windows connection type computation on other thread

net/base/network_change_notifier_win_unittest.cc

Index: net/base/network_change_notifier_win_unittest.cc
diff --git a/net/base/network_change_notifier_win_unittest.cc b/net/base/network_change_notifier_win_unittest.cc
index 40dc42df66da65c94a2253e485e268753f0954bf..fa2e4ecce6efe548f9d654bd0550d8e0e4e6e671 100644
--- a/net/base/network_change_notifier_win_unittest.cc
+++ b/net/base/network_change_notifier_win_unittest.cc
@@ -20,30 +20,9 @@ namespace net {
 
 namespace {
 
-// Subclass of NetworkChangeNotifierWin that overrides functions so that no
-// Windows API networking functions are ever called.
-class TestNetworkChangeNotifierWin : public NetworkChangeNotifierWin {
- public:
-  TestNetworkChangeNotifierWin() {}
-
-  ~TestNetworkChangeNotifierWin() override {
-    // This is needed so we don't try to stop watching for IP address changes,
-    // as we never actually started.
-    set_is_watching(false);
-  }
-
-  // From NetworkChangeNotifierWin.
-  NetworkChangeNotifier::ConnectionType RecomputeCurrentConnectionType()
-      const override {
-    return NetworkChangeNotifier::CONNECTION_UNKNOWN;
-  }
-
-  // From NetworkChangeNotifierWin.
-  MOCK_METHOD0(WatchForAddressChangeInternal, bool());
-
- private:
-  DISALLOW_COPY_AND_ASSIGN(TestNetworkChangeNotifierWin);
-};
+NetworkChangeNotifier::ConnectionType TestRecomputeCurrentConnectionType() {
+  return NetworkChangeNotifier::CONNECTION_UNKNOWN;
+}
 
 class TestIPAddressObserver : public NetworkChangeNotifier::IPAddressObserver {
  public:
@@ -68,6 +47,32 @@ bool ExitMessageLoopAndReturnFalse() {
 
 }  // namespace
 
+// Subclass of NetworkChangeNotifierWin that overrides functions so that no
+// Windows API networking functions are ever called.
+class TestNetworkChangeNotifierWin : public NetworkChangeNotifierWin {
+ public:
+  TestNetworkChangeNotifierWin() {
+    // Use a mocked connection type callback.
+    calculate_connection_type_ =
+        base::BindRepeating(&TestRecomputeCurrentConnectionType);
+
+    // Use this thread for dns tasks instead of a separate thread.
+    dns_task_runner_ = base::ThreadTaskRunnerHandle::Get();
+  }
+
+  ~TestNetworkChangeNotifierWin() override {
+    // This is needed so we don't try to stop watching for IP address changes,
+    // as we never actually started.
+    set_is_watching(false);
+  }
+
+  // From NetworkChangeNotifierWin.
+  MOCK_METHOD0(WatchForAddressChangeInternal, bool());
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(TestNetworkChangeNotifierWin);
+};
+
 class NetworkChangeNotifierWinTest : public testing::Test {
  public:
   // Calls WatchForAddressChange, and simulates a WatchForAddressChangeInternal