CommandLine: add a CopySwitchesFrom() for copying from another CommandLine

chrome/test/ui/sandbox_uitests.cc

 // Copyright (c) 2006-2008 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.
 
 #include <string>
 
 #include "base/command_line.h"
 #include "chrome/common/chrome_switches.h"
 #include "chrome/test/ui/ui_test.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 class SandboxTest : public UITest {
  protected:
   // Launches chrome with the --test-sandbox=security_tests.dll flag.
   SandboxTest() : UITest() {
     launch_arguments_.AppendSwitchWithValue(switches::kTestSandbox,
-                                            L"security_tests.dll");
+                                            "security_tests.dll");
   }
 };
 
 #if !defined(OS_WIN)
 // Need a cross-platform test library: http://crbug.com/45771
 #define ExecuteDll DISABLED_ExecuteDll
 #endif
 // Verifies that chrome is running properly.
 TEST_F(SandboxTest, ExecuteDll) {
   EXPECT_EQ(1, GetTabCount());
 }