b=970773 remove unnecessary IsSafeToRunScript() test on event loop nsRunnable r=roc

If the event loop is running, then it is safe to run script.

--HG--
extra : rebase_source : c0fb5fddb8e714d4d5ed0cdb7384a95cf23ad9af

content/media/webaudio/ScriptProcessorNode.cpp

@@ -383,12 +383,6 @@ private:
 
       NS_IMETHODIMP Run()
       {
-        // If it's not safe to run scripts right now, schedule this to run later
-        if (!nsContentUtils::IsSafeToRunScript()) {
-          nsContentUtils::AddScriptRunner(this);
-          return NS_OK;
-        }
-
         nsRefPtr<ScriptProcessorNode> node;
         {
           // No need to keep holding the lock for the whole duration of this