Fix frequent resetting to initialScale in non-useWideViewport mode.

The oldInitialScale was stored too late after
updatePageDefinedConstraints may have already reset it to -1.  Compare
instead against the value before any constraints processing occurred.

I incorporated this fix into pending upstream patch http://crrev.com/26251010.

BUG: b/11261382
Change-Id: If871048204be595c247e50432bb7f5988eaa8eae
2 files changed