Make sure the root window is large enough to fit the ash's host window size.
Make sure the root window is large enough to fit the ash's host window size.

This is the equivalent to the fix I made in https://codereview.chromium.org/1389503002.

I'm not sure why we have two different scripts to start xvfb. I'll file a separate bug to consolidate them.

BUG=543194

Review URL: https://codereview.chromium.org/1395133003

git-svn-id: 239fca9b83025a0b6f823aeeca02ba5be3d9fd76@297140 0039d316-1c4b-4281-b951-d872f2087c98

eunchong/build,eunchong/build,eunchong/build,eunchong/build