[android_webview] Fix layout in AT_MOST mode.

This is a cherry-pick of http://crrev.com/24163004

> Due to a bug the AwLayoutSizer was ignoring all transitions
> to a content size greater than the AT_MOST height limit even
> if the previous height was less than the AT_MOST limit.
>
> BUG=internal b/10819823

BUG: 10819823
Change-Id: Ifab400b9e10c94a56b8e8eacf98cc55c2b9301a2
2 files changed