Fixes a minor rearrangement of rectangles for display settings.

Fixes a minor rearrangement of rectangles for display settings.

Previously the display rectangles are placed by display object's
x and y, with scaling. However, due to scaling the value and
flooring the scaled result, there could be 1px gap from the
expected position, therefore just clicking may cause sending
the display layout change which causes fade-out and fade-in.

This 1px gap has been there, it's tiny, but it's noticeable.
Therefore this CL rewrites the layouting of display rectangles as
follows:
- first, place the primary display
- then look up the secondary display which is sticking to the
  primary display
This way there cannot be any gaps, therefore doesn't cause any
weird fade-outs.

BUG=386401
R=xiyuan@chromium.org, oshima@chromium.org
TEST=manually

Committed: https://crrev.com/5b0e1a0903ac26a85ceb51bb79b5e4c77d1ff488
Cr-Commit-Position: refs/heads/master@{#304974}

[xiyuan, 2014-11-20 02:21:31]

lgtm

https://codereview.chromium.org/739413002/diff/1/chrome/browser/resources/opt...
File chrome/browser/resources/options/chromeos/display_options.js (right):

https://codereview.chromium.org/739413002/diff/1/chrome/browser/resources/opt...
chrome/browser/resources/options/chromeos/display_options.js:788:
display.div.style.width =
nit: display.div is |div|, why not just use that?

https://codereview.chromium.org/739413002/diff/1/chrome/browser/resources/opt...
chrome/browser/resources/options/chromeos/display_options.js:791:
display.div.style.height = newHeight + 'px';
nit: same here.

[Jun Mukai, 2014-11-20 02:31:41]

https://codereview.chromium.org/739413002/diff/1/chrome/browser/resources/opt...
File chrome/browser/resources/options/chromeos/display_options.js (right):

https://codereview.chromium.org/739413002/diff/1/chrome/browser/resources/opt...
chrome/browser/resources/options/chromeos/display_options.js:788:
display.div.style.width =
On 2014/11/20 02:21:31, xiyuan wrote:
> nit: display.div is |div|, why not just use that?

Done.  I copied from the old code which somehow used display.div for no reason.

https://codereview.chromium.org/739413002/diff/1/chrome/browser/resources/opt...
chrome/browser/resources/options/chromeos/display_options.js:791:
display.div.style.height = newHeight + 'px';
On 2014/11/20 02:21:31, xiyuan wrote:
> nit: same here.

Done.

[Jun Mukai, 2014-11-20 02:33:09]

The CQ bit was checked by mukai@chromium.org

[commit-bot: I haz the power, 2014-11-20 02:35:23]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/739413002/20001

[commit-bot: I haz the power, 2014-11-20 04:33:08]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2014-11-20 04:33:58]

Patchset 2 (id:??) landed as
https://crrev.com/5b0e1a0903ac26a85ceb51bb79b5e4c77d1ff488
Cr-Commit-Position: refs/heads/master@{#304974}