Extracting NetLog inner classes into their own classes.

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 10151f311ac13d91b10b8e97b78b17c13eb0ff48..9c356a885aff0cb383a070d9c12c2f4818b41dce 100644
--- a/net/dns/dns_transaction_unittest.cc
+++ b/net/dns/dns_transaction_unittest.cc
@@ -24,7 +24,7 @@
 #include "net/dns/dns_session.h"
 #include "net/dns/dns_test_util.h"
 #include "net/dns/dns_util.h"
-#include "net/log/net_log.h"
+#include "net/log/net_log_with_source.h"
 #include "net/socket/socket_test_util.h"
 #include "net/test/gtest_util.h"
 #include "testing/gmock/include/gmock/gmock.h"
@@ -34,6 +34,8 @@ using net::test::IsOk;
 
 namespace net {
 
+class NetLog;
+
 namespace {
 
 std::string DomainFromDot(const base::StringPiece& dotted) {
@@ -195,7 +197,7 @@ class TestSocketFactory : public MockClientSocketFactory {
       DatagramSocket::BindType bind_type,
       const RandIntCallback& rand_int_cb,
       NetLog* net_log,
-      const NetLog::Source& source) override {
+      const NetLogSource& source) override {
     if (fail_next_socket_) {
       fail_next_socket_ = false;
       return std::unique_ptr<DatagramClientSocket>(