Switch content tests to use BrowserThreadImpl directly.

content/browser/resolve_proxy_msg_helper_unittest.cc

Index: content/browser/resolve_proxy_msg_helper_unittest.cc
diff --git a/content/browser/resolve_proxy_msg_helper_unittest.cc b/content/browser/resolve_proxy_msg_helper_unittest.cc
index b700f58dbad1bbb744c8fb1d91691c98fbd48ce6..b550b5b79f4fa76e98993572e9dd4f65eb01087b 100644
--- a/content/browser/resolve_proxy_msg_helper_unittest.cc
+++ b/content/browser/resolve_proxy_msg_helper_unittest.cc
@@ -4,8 +4,8 @@
 
 #include "content/browser/resolve_proxy_msg_helper.h"
 
+#include "content/browser/browser_thread_impl.h"
 #include "content/common/view_messages.h"
-#include "content/test/test_browser_thread.h"
 #include "ipc/ipc_test_sink.h"
 #include "net/base/net_errors.h"
 #include "net/proxy/mock_proxy_resolver.h"
@@ -13,6 +13,8 @@
 #include "net/proxy/proxy_service.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
+using content::BrowserThreadImpl;
+
 // This ProxyConfigService always returns "http://pac" as the PAC url to use.
 class MockProxyConfigService : public net::ProxyConfigService {
  public:
@@ -78,7 +80,7 @@ class ResolveProxyMsgHelperTest : public testing::Test,
   }
 
   MessageLoop message_loop_;
-  content::TestBrowserThread io_thread_;
+  BrowserThreadImpl io_thread_;
   IPC::TestSink test_sink_;
 };