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

chrome/browser/nacl_host/test/nacl_gdb_browsertest.cc

Index: chrome/browser/nacl_host/test/nacl_gdb_browsertest.cc
diff --git a/chrome/browser/nacl_host/test/nacl_gdb_browsertest.cc b/chrome/browser/nacl_host/test/nacl_gdb_browsertest.cc
index 25bbb3ba5fe812940d1ca740942319028659bdf1..b7d7f4c0230d14a9ddfd86ed76959825a9e1b1c2 100644
--- a/chrome/browser/nacl_host/test/nacl_gdb_browsertest.cc
+++ b/chrome/browser/nacl_host/test/nacl_gdb_browsertest.cc
@@ -23,7 +23,7 @@ class NaClGdbTest : public PPAPINaClNewlibTest {
   NaClGdbTest() {
   }
 
-  void SetUpCommandLine(CommandLine* command_line) override {
+  void SetUpCommandLine(base::CommandLine* command_line) override {
     PPAPINaClNewlibTest::SetUpCommandLine(command_line);
 
     base::FilePath mock_nacl_gdb;