Run the perf bots with FCM disabled to see what the effect is.

BUG=281709

Review URL: https://chromiumcodereview.appspot.com/23483021

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@220704 0039d316-1c4b-4281-b951-d872f2087c98

tools/telemetry/telemetry/core/backends/chrome/desktop_browser_backend.py

@@ -97,6 +97,9 @@ class DesktopBrowserBackend(chrome_browser_backend.ChromeBrowserBackend):
     args = super(DesktopBrowserBackend, self).GetBrowserStartupArgs()
     args.append('--remote-debugging-port=%i' % self._port)
     args.append('--enable-crash-reporter-for-testing')
+    # Temporarily disable compositing to see the effect on performance results.
+    # http://crbug.com/281709
+    args.append('--disable-force-compositing-mode')
     if not self.is_content_shell:
       args.append('--window-size=1280,1024')
       if self._flash_path: