Refactor net tests to use GMock matchers for checking net::Error results

net/dns/dns_transaction_unittest.cc

Index: net/dns/dns_transaction_unittest.cc
diff --git a/net/dns/dns_transaction_unittest.cc b/net/dns/dns_transaction_unittest.cc
index b33c8a655216f8a3d56da89c5e51f5d0e9cac8af..2e7ef641f953e682a1f9bbbd0c56293a88bc286f 100644
--- a/net/dns/dns_transaction_unittest.cc
+++ b/net/dns/dns_transaction_unittest.cc
@@ -26,8 +26,12 @@
 #include "net/dns/dns_util.h"
 #include "net/log/net_log.h"
 #include "net/socket/socket_test_util.h"
+#include "net/test/gtest_util.h"
+#include "testing/gmock/include/gmock/gmock.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
+using net::test::IsOk;
+
 namespace net {
 
 namespace {
@@ -281,7 +285,7 @@ class TransactionHelper {
       base::MessageLoop::current()->QuitWhenIdle();
 
     if (expected_answer_count_ >= 0) {
-      ASSERT_EQ(OK, rv);
+      ASSERT_THAT(rv, IsOk());
       ASSERT_TRUE(response != NULL);
       EXPECT_EQ(static_cast<unsigned>(expected_answer_count_),
                 response->answer_count());