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

content/renderer/browser_render_view_browsertest.cc

Index: content/renderer/browser_render_view_browsertest.cc
diff --git a/content/renderer/browser_render_view_browsertest.cc b/content/renderer/browser_render_view_browsertest.cc
index 2c12bc7a4788eee293d916c21a312015f28161c9..328a4efe39815d5a789bc40b948541996dee15b7 100644
--- a/content/renderer/browser_render_view_browsertest.cc
+++ b/content/renderer/browser_render_view_browsertest.cc
@@ -137,7 +137,7 @@ class RenderViewBrowserTest : public ContentBrowserTest {
  public:
   RenderViewBrowserTest() {}
 
-  void SetUpCommandLine(CommandLine* command_line) override {
+  void SetUpCommandLine(base::CommandLine* command_line) override {
     // This method is needed to allow interaction with in-process renderer
     // and use of a test ContentRendererClient.
     command_line->AppendSwitch(switches::kSingleProcess);