Open PDF in Browser SharePoint

I wanted my web app to allow opening of PDF files in the browser. I performed the action below which solved the issue.

$webApplication = Get-SPWebApplication "http:/yourwebapplicationurl" 
$webAppApplication.AllowedInlineDownloadedMimeTypes.Add("application/pdf") 
$webApplication.Update() 

As a test I removed that ability with the script below.

$webApplication = Get-SPWebApplication "http:/yourwebapplicationurl" 
$webApplication.AllowedInlineDownloadedMimeTypes.Remove("application/pdf") 
$webApplication.Update()

The problem was that I was still able to open PDF files in the browser after reverting my change. Any ideas why this occured? I tried restarting SharePoint services and IIS.