Return primary display if out of bounds point or NULL ponter is passed to gfx::Screen::GeDisplayNea

Return primary display if out of bounds point or NULL ponter is passed to gfx::Screen::GeDisplayNea

I also changed to use just id to remember primary display.
Update window resizer test to use screen coordinates.

BUG=151196
TEST=covered by test.

Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=157866

[sky, 2012-09-20 19:46:22]

LGTM

[commit-bot: I haz the power, 2012-09-20 20:36:12]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/oshima@chromium.org/10961021/10001

[commit-bot: I haz the power, 2012-09-20 20:40:38]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/oshima@chromium.org/10961021/22

[oshima, 2012-09-20 20:47:27]

On 2012/09/20 19:46:22, sky wrote:
> LGTM

I had to fix a few more tests. 
WindowDragWithMultiDisplays
WindowDragWithMultiDisplaysRightToLeft
PhantomStyle

These must have updated in mazda-san's nice cleanup CL, but they were
passing by coincident. (displays_[0] was 2nd I think). Let me know
if you find any issue, otherwise, i'll let CQ going.

[commit-bot: I haz the power, 2012-09-20 23:17:14]

Change committed as 157866