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

chrome/browser/media/chrome_webrtc_webcam_browsertest.cc

 // Copyright 2014 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 "base/command_line.h"
 #include "chrome/browser/media/webrtc_browsertest_base.h"
 #include "chrome/browser/media/webrtc_browsertest_common.h"
 #include "chrome/browser/ui/browser.h"
 #include "chrome/browser/ui/browser_tabstrip.h"
 #include "chrome/browser/ui/tabs/tab_strip_model.h"
@@ skipping 21 matching lines @@
   NULL
 #endif
 };
 
 // These tests runs on real webcams and ensure WebRTC can acquire webcams
 // correctly. They will do nothing if there are no webcams on the system.
 // The webcam on the system must support up to 1080p, or the test will fail.
 class WebRtcWebcamBrowserTest : public WebRtcTestBase,
     public testing::WithParamInterface<const char*> {
  public:
-  void SetUpCommandLine(CommandLine* command_line) override {
+  void SetUpCommandLine(base::CommandLine* command_line) override {
     EXPECT_FALSE(command_line->HasSwitch(
         switches::kUseFakeDeviceForMediaStream));
     EXPECT_FALSE(command_line->HasSwitch(
         switches::kUseFakeUIForMediaStream));
     if (GetParam())
       command_line->AppendSwitch(GetParam());
   }
 
  protected:
   void SetUpInProcessBrowserTestFixture() override {
@@ skipping 51 matching lines @@
 
   EXPECT_EQ("1280x720",
             GetUserMediaAndGetStreamSize(tab, kVideoCallConstraints720p));
   EXPECT_EQ("1920x1080",
             GetUserMediaAndGetStreamSize(tab, kVideoCallConstraints1080p));
 }
 
 INSTANTIATE_TEST_CASE_P(WebRtcWebcamBrowserTests,
                         WebRtcWebcamBrowserTest,
                         testing::ValuesIn(kTestConfigFlags));