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

chrome/browser/extensions/process_management_browsertest.cc

Index: chrome/browser/extensions/process_management_browsertest.cc
diff --git a/chrome/browser/extensions/process_management_browsertest.cc b/chrome/browser/extensions/process_management_browsertest.cc
index 97c5b2562989fb780c7e0214bb0af883ed875d48..fc1532e6a762ae9b858e7d3abe90bb7f5f7a533f 100644
--- a/chrome/browser/extensions/process_management_browsertest.cc
+++ b/chrome/browser/extensions/process_management_browsertest.cc
@@ -29,7 +29,7 @@ namespace {
 class ProcessManagementTest : public ExtensionBrowserTest {
  private:
   // This is needed for testing isolated apps, which are still experimental.
-  void SetUpCommandLine(CommandLine* command_line) override {
+  void SetUpCommandLine(base::CommandLine* command_line) override {
     ExtensionBrowserTest::SetUpCommandLine(command_line);
     command_line->AppendSwitch(
         extensions::switches::kEnableExperimentalExtensionApis);