Revert of Removed duplicated JS hasVideoInputDeviceOnSystem() test helper

chrome/browser/media/webrtc/webrtc_browsertest_base.cc

Index: chrome/browser/media/webrtc/webrtc_browsertest_base.cc
diff --git a/chrome/browser/media/webrtc/webrtc_browsertest_base.cc b/chrome/browser/media/webrtc/webrtc_browsertest_base.cc
index 6c3bcd69d14c126600b2f78f7ee03e5a8a573245..d1242fb8f211f876ad7c1ec1d0003fd6f8216aba 100644
--- a/chrome/browser/media/webrtc/webrtc_browsertest_base.cc
+++ b/chrome/browser/media/webrtc/webrtc_browsertest_base.cc
@@ -428,6 +428,13 @@
   return result.substr(3);
 }
 
+bool WebRtcTestBase::HasWebcamAvailableOnSystem(
+    content::WebContents* tab_contents) const {
+  std::string result =
+      ExecuteJavascript("hasVideoInputDeviceOnSystem();", tab_contents);
+  return result == "has-video-input-device";
+}
+
 bool WebRtcTestBase::OnWin8() const {
 #if defined(OS_WIN)
   return base::win::GetVersion() > base::win::VERSION_WIN7;