Telemetry: Fix facebook.com on key_mobile_sites.

Telemetry: Fix facebook.com on key_mobile_sites.

The facebook.com page sometimes wouldn't scroll, because the scroll height
would be equal to the window height. The page seems to dynamically load
elements and scroll height only gets updated after that. To avoid this
problem, this CL makes telemetry wait until the value for scroll height
has been updated.

BUG=238864
R=tonyg@chromium.org

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=221416

[Dominik Grewe, 2013-09-04 16:39:50]

PTAL, thanks!

[tonyg, 2013-09-04 17:27:19]

https://codereview.chromium.org/23957002/diff/1/tools/perf/page_sets/key_mobi...
File tools/perf/page_sets/key_mobile_sites.json (right):

https://codereview.chromium.org/23957002/diff/1/tools/perf/page_sets/key_mobi...
tools/perf/page_sets/key_mobile_sites.json:73: { "action": "wait", "javascript":
"document.getElementById('u_0_c') !== null && document.body.scrollHeight >
window.innerHeight" }
Does this work for all screen sizes? I'm worried that it might only work on
smaller screens.

[Dominik Grewe, 2013-09-04 20:05:52]

https://codereview.chromium.org/23957002/diff/1/tools/perf/page_sets/key_mobi...
File tools/perf/page_sets/key_mobile_sites.json (right):

https://codereview.chromium.org/23957002/diff/1/tools/perf/page_sets/key_mobi...
tools/perf/page_sets/key_mobile_sites.json:73: { "action": "wait", "javascript":
"document.getElementById('u_0_c') !== null && document.body.scrollHeight >
window.innerHeight" }
On 2013/09/04 17:27:19, tonyg wrote:
> Does this work for all screen sizes? I'm worried that it might only work on
> smaller screens.

It should work if there's anything to scroll :) An alternative would be to wait
for a second or so to make sure the values have been updated.

[tonyg, 2013-09-04 20:29:43]

lgtm

https://codereview.chromium.org/23957002/diff/1/tools/perf/page_sets/key_mobi...
File tools/perf/page_sets/key_mobile_sites.json (right):

https://codereview.chromium.org/23957002/diff/1/tools/perf/page_sets/key_mobi...
tools/perf/page_sets/key_mobile_sites.json:73: { "action": "wait", "javascript":
"document.getElementById('u_0_c') !== null && document.body.scrollHeight >
window.innerHeight" }
On 2013/09/04 20:05:52, Dominik Grewe wrote:
> On 2013/09/04 17:27:19, tonyg wrote:
> > Does this work for all screen sizes? I'm worried that it might only work on
> > smaller screens.
> 
> It should work if there's anything to scroll :) An alternative would be to
wait
> for a second or so to make sure the values have been updated.

You are right. The test will fail anyway if there is nothing to scroll.

[Sami, 2013-09-05 14:23:01]

Committed patchset #1 manually as r221416 (presubmit successful).