Fix form regression on salesforce.com the right way

This reverts the code changes in http://src.chromium.org/viewvc/blink?view=revision&revision=161672.

Only mark ScheduledFormSubmissions as a location change if we know they will be navigating the current frame. Otherwise, if the document is still parsing and the form submission ends up in another frame, the parser will drop everything after the form submission in the current frame, even though it isn't navigating.

BUG=308402

Review URL: https://codereview.chromium.org/68893005

git-svn-id: svn://svn.chromium.org/blink/trunk@161848 bbb929c8-8fbe-4397-9dbb-9b2b20218538