Reset host resolver in unittest

chromeos/network/host_resolver_impl_chromeos_unittest.cc

 // Copyright 2014 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 "chromeos/network/host_resolver_impl_chromeos.h"
 
 #include "base/memory/scoped_ptr.h"
 #include "base/message_loop/message_loop.h"
 #include "base/run_loop.h"
 #include "base/strings/stringprintf.h"
@@ skipping 50 matching lines @@
         base::Bind(&HostResolverImplChromeOSTest::InitializeHostResolver,
                    base::Unretained(this)));
     io_message_loop_.RunUntilIdle();
 
     // Run the main message loop to create the network observer and initialize
     // the ip address values.
     base::RunLoop().RunUntilIdle();
   }
 
   virtual void TearDown() OVERRIDE {
+    host_resolver_.reset();
     network_state_handler_.reset();
     chromeos::DBusThreadManager::Shutdown();
   }
 
  protected:
   // Run from main (UI) message loop, calls Resolve on IO message loop.
   int CallResolve(net::HostResolver::RequestInfo& info) {
     io_message_loop_.PostTask(
         FROM_HERE,
         base::Bind(&HostResolverImplChromeOSTest::Resolve,
@@ skipping 82 matching lines @@
   EXPECT_EQ(expected, addresses_[0].ToString());
 
   info.set_address_family(net::ADDRESS_FAMILY_IPV6);
   EXPECT_EQ(net::OK, CallResolve(info));
   ASSERT_EQ(2u, addresses_.size());
   expected = base::StringPrintf("[%s]:%d", kTestIPv6Address, 0);
   EXPECT_EQ(expected, addresses_[0].ToString());
   expected = base::StringPrintf("%s:%d", kTestIPv4Address, 0);
   EXPECT_EQ(expected, addresses_[1].ToString());
 }