[browser] Address bar and tabs disappears when loading a page

[Víctor R. Ruiz]

Test case.
- Open webbrowser app in a phone device.
- Introduce a URL in the address box.

Expected result.
- The address bar is always kept visible.

Actual result.
- While the page is loading, the address bar disappears for a moment. This is annoying, specially when the address box is being used to enter a new address.

current build number: 36
device name: krillin
channel: ubuntu-touch/stable/bq-aquaris.en

webbrowser-app:
  Installed: 0.23+15.04.20170124.1-0ubuntu1
  Candidate: 0.23+15.04.20170124.1-0ubuntu1
  Version table:
 *** 0.23+15.04.20170124.1-0ubuntu1 0
       1001 http://ppa.launchpad.net/ci-train-ppa-service/stable-snapshot/ubuntu/ vivid/main armhf Packages

liboxideqtcore0:
  Installed: 1.19.7-0ubuntu0.15.04.1~overlay1
  Candidate: 1.19.7-0ubuntu0.15.04.1~overlay1
  Version table:
 *** 1.19.7-0ubuntu0.15.04.1~overlay1 0
       1001 http://ppa.launchpad.net/ci-train-ppa-service/stable-snapshot/ubuntu/ vivid/main armhf Packages

[Olivier Tilloy (osomon)]

I initially suspected that it might be webbrowser-app not handling well the chrome, but I can reliably observe the issue on my desktop with oxide 1.19.7 running the simple QML example attached.

Open it with qmlscene and click on the red rectangle at the top to load new pages. It can be clearly seen that the rectangle briefly disappears before being painted again when loading a new page, and the console output shows that the offset indeed briefly changes to -100 and then to 0 again. The offset shouldn’t change.

[Olivier Tilloy (osomon)]

It appears that the offset is reset only when navigating to a new domain. In the simple reproducer attached to comment #1, if I set all the URLs to belong to the same domain, the offset is never reset.