Merge changes I5c891dc1,Ie717089d
am: f736a55d84

* commit 'f736a55d849d18767b827e7efeb9114f80e4e660':
  Base isDexOptNeeded result on OatFileAssistant::IsUpToDate.
  Only compile dex files if they are not up to date.

Change-Id: I97f48400d49f8ee67bfd9179e3b2f0ff93f19cb9