Refactor media stream infobar delegate code and also fix a typo

chrome/browser/automation/testing_automation_provider.cc

Index: chrome/browser/automation/testing_automation_provider.cc
diff --git a/chrome/browser/automation/testing_automation_provider.cc b/chrome/browser/automation/testing_automation_provider.cc
index 64ba390ef1a4d0a3e10d4f109b5479ffdb9cf7d9..9033f9fdbdbbbffa1ef109ee16da317966a129e9 100644
--- a/chrome/browser/automation/testing_automation_provider.cc
+++ b/chrome/browser/automation/testing_automation_provider.cc
@@ -2700,7 +2700,7 @@ void TestingAutomationProvider::PerformActionOnInfobar(
   }
   if ("allow" == action || "deny" == action) {
     MediaStreamInfoBarDelegate* media_stream_infobar;
-    if (!(media_stream_infobar = infobar->AsMediaStreamInfobarDelegate())) {
+    if (!(media_stream_infobar = infobar->AsMediaStreamInfoBarDelegate())) {
       reply.SendError("Not a media stream infobar.");
       return;
     }