Revert of Removed duplicated JS hasVideoInputDeviceOnSystem() test helper

chrome/browser/media/webrtc/webrtc_browsertest_base.h

 // Copyright 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.
 
 #ifndef CHROME_BROWSER_MEDIA_WEBRTC_WEBRTC_BROWSERTEST_BASE_H_
 #define CHROME_BROWSER_MEDIA_WEBRTC_WEBRTC_BROWSERTEST_BASE_H_
 
 #include <string>
 
 #include "base/macros.h"
@@ skipping 133 matching lines @@
   // chrome/test/data/webrtc/video_detector.js and its dependencies loaded to
   // make that work). Looks at a 320x240 area of the target video tag.
   void StartDetectingVideo(content::WebContents* tab_contents,
                            const std::string& video_element) const;
   bool WaitForVideoToPlay(content::WebContents* tab_contents) const;
 
   // Returns the stream size as a string on the format <width>x<height>.
   std::string GetStreamSize(content::WebContents* tab_contents,
                             const std::string& video_element) const;
 
+  // Methods to check what devices we have on the system.
+  bool HasWebcamAvailableOnSystem(content::WebContents* tab_contents) const;
+
   // Returns true if we're on win 8.
   bool OnWin8() const;
 
   void OpenDatabase(content::WebContents* tab) const;
   void CloseDatabase(content::WebContents* tab) const;
   void DeleteDatabase(content::WebContents* tab) const;
 
   void GenerateAndCloneCertificate(content::WebContents* tab,
                                    const std::string& keygen_algorithm) const;
 
@@ skipping 21 matching lines @@
   infobars::InfoBar* GetUserMediaAndWaitForInfoBar(
       content::WebContents* tab_contents,
       const std::string& constraints) const;
 
   bool detect_errors_in_javascript_;
 
   DISALLOW_COPY_AND_ASSIGN(WebRtcTestBase);
 };
 
 #endif  // CHROME_BROWSER_MEDIA_WEBRTC_WEBRTC_BROWSERTEST_BASE_H_