title: inspecting mobile web page with chrome devtools results in blank screen
body: <p>Debugging a web page running in Chrome on Android (Galaxy S8) via the USB connection in the latest version of the Chrome desktop browser is not working.
  Attempting to inspect web pages running on the mobile device results in a
  <a href="https://i.stack.imgur.com/QTrlF.png" rel="nofollow noreferrer">blank page</a>.</p>
  
  <p>When I inspect the blank page that appears in the desktop Chrome browser, I get the <a href="https://i.stack.imgur.com/X2fpA.png" rel="nofollow noreferrer">following error</a>:</p>
  
  <pre><code>Uncaught TypeError: InspectorFrontendHost.isUnderTest is not a function
      at Object.Host.isUnderTest (inspector.js:930)
      at Main.Main._gotPreferences (inspector.js:8301)
      at DevToolsAPIImpl.embedderMessageAck (devtools_compatibility.js:33)
      at &lt;anonymous&gt;:1:13
  </code></pre>