Merge pull request #15252 from comoyo/bug953400_v2

Bug 953400 - Give exact matches a little weight boost in autocorrect. r=djf
Merge pull request #16399 from comoyo/972276

Bug 972276 - Cache window size on event to avoid reflows. r=RudyLu
Bug 964739 - Call resizeUI on keyboard if orientation changed since last time