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

chrome/browser/errorpage_browsertest.cc

Index: chrome/browser/errorpage_browsertest.cc
diff --git a/chrome/browser/errorpage_browsertest.cc b/chrome/browser/errorpage_browsertest.cc
index 7347c895d6d67b799b316f44366dafde8a1e44ad..289898ba331654b0b36de87b250d5711f87d3738 100644
--- a/chrome/browser/errorpage_browsertest.cc
+++ b/chrome/browser/errorpage_browsertest.cc
@@ -297,7 +297,7 @@ class ErrorPageTest : public InProcessBrowserTest {
 
   // Navigates the active tab to a mock url created for the file at |file_path|.
   // Needed for StaleCacheStatus and StaleCacheStatusFailedCorrections tests.
-  void SetUpCommandLine(CommandLine* command_line) override {
+  void SetUpCommandLine(base::CommandLine* command_line) override {
     command_line->AppendSwitch(switches::kEnableOfflineLoadStaleCache);
   }
 
@@ -874,7 +874,7 @@ IN_PROC_BROWSER_TEST_F(ErrorPageTest, StaleCacheStatus) {
 
 class ErrorPageAutoReloadTest : public InProcessBrowserTest {
  public:
-  void SetUpCommandLine(CommandLine* command_line) override {
+  void SetUpCommandLine(base::CommandLine* command_line) override {
     command_line->AppendSwitch(switches::kEnableOfflineAutoReload);
   }