Chameleon: Remove redundant waiting for 2-display-info appearing in chrome

While waiting for the external display connected after a plug or so on,
there were 2 waiting conditions:
 - waiting the name of the external display appearing in xrandr;
 - waiting the number of the display infos in chrome being 2.

The latter is redundant. It introduces some flaky errors randomly,
like the bug of http://crbug.com/397322. Removing this redunant waiting
helps.

BUG=chromium:397322
TEST=Passed display_Resolution.mirrored and display_ResolutionList.extended

Change-Id: I9e8a3a67d60b28f3bb4090fc00c7b0782cee1da0
Reviewed-on: https://chromium-review.googlesource.com/222900
Tested-by: Wai-Hong Tam <waihong@chromium.org>
Reviewed-by: Hung-ying Tyan <tyanh@chromium.org>
Commit-Queue: Wai-Hong Tam <waihong@chromium.org>
1 file changed