Revert of Removed duplicated JS hasVideoInputDeviceOnSystem() test helper

chrome/browser/media/webrtc/webrtc_browsertest_base.h

Index: chrome/browser/media/webrtc/webrtc_browsertest_base.h
diff --git a/chrome/browser/media/webrtc/webrtc_browsertest_base.h b/chrome/browser/media/webrtc/webrtc_browsertest_base.h
index c33b2f514b47806ab671079829daa91a9f330e5a..1857bc7b787faffabb79db2ac59f9af5e51ef1ee 100644
--- a/chrome/browser/media/webrtc/webrtc_browsertest_base.h
+++ b/chrome/browser/media/webrtc/webrtc_browsertest_base.h
@@ -151,6 +151,9 @@
   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;