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

tools/set_default_handler/set_default_handler_main.cc

 // Copyright (c) 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // Makes a given program ("Google Chrome" by default) the default handler for
 // some URL protocol ("http" by default) on Windows 8. These defaults can be
 // overridden via the --program and --protocol command line switches.
 
 #include <windows.h>
 
@@ skipping 10 matching lines @@
 const char kSwitchProgram[] = "program";
 const char kSwitchProtocol[] = "protocol";
 const wchar_t kDefaultProgram[] = L"Google Chrome";
 const wchar_t kDefaultProtocol[] = L"http";
 
 }  // namespace
 
 extern "C"
 int wmain(int argc, wchar_t* argv[]) {
   // Initialize the commandline singleton from the environment.
-  CommandLine::Init(0, NULL);
+  base::CommandLine::Init(0, NULL);
   // The exit manager is in charge of calling the dtors of singletons.
   base::AtExitManager exit_manager;
   logging::LoggingSettings settings;
   settings.logging_dest = logging::LOG_TO_SYSTEM_DEBUG_LOG;
   logging::InitLogging(settings);
   logging::SetMinLogLevel(logging::LOG_VERBOSE);
 
   ui::win::CreateATLModuleIfNeeded();
 
-  CommandLine* command_line = CommandLine::ForCurrentProcess();
+  base::CommandLine* command_line = base::CommandLine::ForCurrentProcess();
   base::string16 protocol(command_line->GetSwitchValueNative(kSwitchProtocol));
   if (protocol.empty())
     protocol = kDefaultProtocol;
 
   base::string16 program(command_line->GetSwitchValueNative(kSwitchProgram));
   if (program.empty())
     program = kDefaultProgram;
 
   std::vector<base::string16> choices;
   HRESULT result = S_OK;
   win8::OpenWithDialogController controller;
   result = controller.RunSynchronously(NULL, protocol, program, &choices);
 
   if (SUCCEEDED(result)) {
     printf("success\n");
   } else if (!choices.empty()) {
     printf("failed to set program. possible choices: %ls\n",
            JoinString(choices, L", ").c_str());
   } else {
     printf("failed with HRESULT: %0x08X\n", result);
   }
 
   return FAILED(result);
 }