Add a scroll threshold/marker to control hiding/showing top controls.

Add a scroll limit to control hiding/showing top controls.

When starting a scroll gesture, mark a initial scroll marker
and do not hide the top controls when above the marker and
do not show the controls when below (further down the page)
the threshold.

BUG=161303
Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=178749

[David Trainor- moved to gerrit, 2013-01-23 19:21:08]

lgtm

[Ted C, 2013-01-24 17:47:45]

+james|enne - owners approval

[jamesr, 2013-01-24 22:05:28]

lgtm

https://codereview.chromium.org/11953040/diff/1/cc/top_controls_manager_unitt...
File cc/top_controls_manager_unittest.cc (right):

https://codereview.chromium.org/11953040/diff/1/cc/top_controls_manager_unitt...
cc/top_controls_manager_unittest.cc:144: TEST(TopControlsManagerTest,
enssureScrollThresholdApplied) {
typo "enssure" -> "ensure"

[Ted C, 2013-01-24 23:56:01]

https://codereview.chromium.org/11953040/diff/1/cc/top_controls_manager_unitt...
File cc/top_controls_manager_unittest.cc (right):

https://codereview.chromium.org/11953040/diff/1/cc/top_controls_manager_unitt...
cc/top_controls_manager_unittest.cc:144: TEST(TopControlsManagerTest,
enssureScrollThresholdApplied) {
On 2013/01/24 22:05:29, jamesr wrote:
> typo "enssure" -> "ensure"

Done.

[commit-bot: I haz the power, 2013-01-24 23:57:29]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/tedchoc@chromium.org/11953040/5001

[commit-bot: I haz the power, 2013-01-25 02:32:24]

Retried try job too often on mac_rel for step(s) browser_tests
http://build.chromium.org/p/tryserver.chromium/buildstatus?builder=mac_rel&nu...

[commit-bot: I haz the power, 2013-01-25 03:08:50]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/tedchoc@chromium.org/11953040/5001

[commit-bot: I haz the power, 2013-01-25 04:38:56]

Change committed as 178749