Make callers of CommandLine use it via the base:: namespace.

chrome/browser/chromeos/login/login_utils_browsertest.cc

Index: chrome/browser/chromeos/login/login_utils_browsertest.cc
diff --git a/chrome/browser/chromeos/login/login_utils_browsertest.cc b/chrome/browser/chromeos/login/login_utils_browsertest.cc
index 077e87e020fa85a59478f57fb7034566feef7505..da5c7d8764671b7d8655788c319d3b93f7a72022 100644
--- a/chrome/browser/chromeos/login/login_utils_browsertest.cc
+++ b/chrome/browser/chromeos/login/login_utils_browsertest.cc
@@ -46,7 +46,7 @@ class LoginUtilsTest : public InProcessBrowserTest {
  public:
   LoginUtilsTest() {}
 
-  virtual void SetUpCommandLine(CommandLine* command_line) override {
+  virtual void SetUpCommandLine(base::CommandLine* command_line) override {
     // Initialize the test server early, so that we can use its base url for
     // the command line flags.
     ASSERT_TRUE(embedded_test_server()->InitializeAndWaitUntilReady());