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

chrome/browser/extensions/api/cast_streaming/cast_streaming_apitest.cc

Index: chrome/browser/extensions/api/cast_streaming/cast_streaming_apitest.cc
diff --git a/chrome/browser/extensions/api/cast_streaming/cast_streaming_apitest.cc b/chrome/browser/extensions/api/cast_streaming/cast_streaming_apitest.cc
index 21d88285de5c09930875b192bfba0e819647ed01..b8c535660179b9d88270165515a27e895f235d11 100644
--- a/chrome/browser/extensions/api/cast_streaming/cast_streaming_apitest.cc
+++ b/chrome/browser/extensions/api/cast_streaming/cast_streaming_apitest.cc
@@ -37,7 +37,7 @@ namespace extensions {
 
 class CastStreamingApiTest : public ExtensionApiTest {
  public:
-  void SetUpCommandLine(CommandLine* command_line) override {
+  void SetUpCommandLine(base::CommandLine* command_line) override {
     ExtensionApiTest::SetUpCommandLine(command_line);
     command_line->AppendSwitchASCII(
         extensions::switches::kWhitelistedExtensionID,
@@ -321,7 +321,7 @@ class CastStreamingApiTestWithPixelOutput : public CastStreamingApiTest {
     CastStreamingApiTest::SetUp();
   }
 
-  void SetUpCommandLine(CommandLine* command_line) override {
+  void SetUpCommandLine(base::CommandLine* command_line) override {
     command_line->AppendSwitchASCII(::switches::kWindowSize, "128,128");
     CastStreamingApiTest::SetUpCommandLine(command_line);
   }