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

chrome/browser/printing/printing_layout_browsertest.cc

Index: chrome/browser/printing/printing_layout_browsertest.cc
diff --git a/chrome/browser/printing/printing_layout_browsertest.cc b/chrome/browser/printing/printing_layout_browsertest.cc
index cc593ba392fd89533ee8f2979c347a424199228e..277c507333dff7d33ba3fbe7c09574cea02e4e59 100644
--- a/chrome/browser/printing/printing_layout_browsertest.cc
+++ b/chrome/browser/printing/printing_layout_browsertest.cc
@@ -56,7 +56,7 @@ class PrintingLayoutTest : public PrintingTest<InProcessBrowserTest>,
     base::DeleteFile(emf_path_, true);
   }
 
-  virtual void SetUpCommandLine(CommandLine* command_line) override {
+  virtual void SetUpCommandLine(base::CommandLine* command_line) override {
     command_line->AppendSwitchPath(switches::kDebugPrint, emf_path_);
   }
 
@@ -236,7 +236,7 @@ class PrintingLayoutTest : public PrintingTest<InProcessBrowserTest>,
   }
 
   static bool GenerateFiles() {
-    return CommandLine::ForCurrentProcess()->HasSwitch(kGenerateSwitch);
+    return base::CommandLine::ForCurrentProcess()->HasSwitch(kGenerateSwitch);
   }
 
   base::FilePath emf_path_;