Revert of Removed duplicated JS hasVideoInputDeviceOnSystem() test helper

content/public/test/browser_test_utils.h

Index: content/public/test/browser_test_utils.h
diff --git a/content/public/test/browser_test_utils.h b/content/public/test/browser_test_utils.h
index 96e5791db23ffa2612bb2a19662a285647173c32..964cf670722fe525c0cf0d91b80292d103c2d9f5 100644
--- a/content/public/test/browser_test_utils.h
+++ b/content/public/test/browser_test_utils.h
@@ -166,9 +166,6 @@
                       bool alt,
                       bool command);
 
-// Method to check what devices we have on the system.
-bool IsWebcamAvailableOnSystem(WebContents* web_contents);
-
 // Allow ExecuteScript* methods to target either a WebContents or a
 // RenderFrameHost.  Targetting a WebContents means executing the script in the
 // RenderFrameHost returned by WebContents::GetMainFrame(), which is the main