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

chrome/browser/chromeos/policy/blocking_login_browsertest.cc

Index: chrome/browser/chromeos/policy/blocking_login_browsertest.cc
diff --git a/chrome/browser/chromeos/policy/blocking_login_browsertest.cc b/chrome/browser/chromeos/policy/blocking_login_browsertest.cc
index c0f75339262ed8589d869aeeed3337198fda646f..821136f45ab0d5d88812239052f626c4c7385c00 100644
--- a/chrome/browser/chromeos/policy/blocking_login_browsertest.cc
+++ b/chrome/browser/chromeos/policy/blocking_login_browsertest.cc
@@ -87,7 +87,7 @@ class BlockingLoginTest
  public:
   BlockingLoginTest() : profile_added_(NULL) {}
 
-  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());