scrollbars incorrect in Facebook (and other) webapps

I think I know what’s going on: to determine which kind of scrollbars it should display, oxide queries the form factor. And to detect a phone or tablet, the current implementation tries to enumerate udev devices matching "android_usb". Application confinement for the webapp container means that it’s not allowed to perform this kind of query, and it therefore assumes desktop form factor:

Apr 3 10:08:10 ubuntu-phablet kernel: [ 9234.082092] type=1400 audit(1396519690.090:296): apparmor="DENIED" operation="open" parent=4734 profile="com.ubuntu.developer.webapps.webapp-facebook_webapp-facebook_1.0.11//oxide_helper" name="/proc/sys/kernel/yama/ptrace_scope" pid=4735 comm="oxide-renderer" requested_mask="r" denied_mask="r" fsuid=32011 ouid=0

After discussing the issue with Chris, it appears that the best approach would be not to use udev to detect the form factor. Instead, Chris suggests using eglQueryString to check EGL_VENDOR (assuming it will have something android related in it).

This can be done by dlopening and manually binding the symbol, rather than using chromium's GL bindings (which won't work correctly from there).

FYI, this ptrace denial was fixed in apaprmor-easyprof-ubuntu 1.1.13.

This bug was fixed in the package oxide-qt - 1.0.0~bzr475-0ubuntu1

---------------
oxide-qt (1.0.0~bzr475-0ubuntu1) trusty; urgency=medium

  * Update to r475
    - Update to Chromium 35.0.1916.6
    - If WebView.newViewRequested isn't implemented, navigations should happen
      in the originating view
    - Refine WebView.newViewRequested and WebView.navigationRequested API's
      (LP: #1300891)
    - Improve the form factor detection (LP: #1301678)
    - Add WebView.javaScriptConsoleMessage signal to allow the application
      to intercept console messages from content (LP: #1291389)
    - Improve the LoadEvent API
    - Fix an abort when setting WebContext.sessionCookieMode on a context
      that has no path (LP: #1301650)
    - Expose the default WebContext via Oxide.defaultWebContext() (LP: #1297552)
    - Send fake keydown and keyup events when composing text with an
      input method (LP: #1300382)
    - Bump the API version to 1.0
 -- Chris Coulson <email address hidden> Fri, 04 Apr 2014 19:28:27 +0100