Add functionality to get default media device IDs from user preferences.

chrome/browser/ui/browser.cc

Index: chrome/browser/ui/browser.cc
diff --git a/chrome/browser/ui/browser.cc b/chrome/browser/ui/browser.cc
index b64ad9188e41876adfbc062c9ba58453894c622b..c489ed9e64df1dcb9ad35ea33358b79a3359ec00 100644
--- a/chrome/browser/ui/browser.cc
+++ b/chrome/browser/ui/browser.cc
@@ -1824,6 +1824,11 @@ bool Browser::CheckMediaAccessPermission(content::WebContents* web_contents,
   return ::CheckMediaAccessPermission(web_contents, security_origin, type);
 }
 
+std::string Browser::GetDefaultMediaDeviceId(content::WebContents* web_contents,
+                                             content::MediaStreamType type) {
+  return ::GetDefaultMediaDeviceId(web_contents, type);
+}
+
 bool Browser::RequestPpapiBrokerPermission(
     WebContents* web_contents,
     const GURL& url,