Merge commit 'a8f0f77b2e3eed77e97dd7ddd553e0dccefaf265'
* commit 'a8f0f77b2e3eed77e97dd7ddd553e0dccefaf265':
Avoid the rounding error, as Math.round(Math.round(viewWidth * mInvActualScale) * mActualScale) not necessary to be viewWidth, we special case when the content exactly fit in the view case.