When cancelling parsing of a document, try to transition to completed

With browser side navigations, we might cancel parsing because a new
navigation started, which in turn might fail. In that case, the original
document should be in a defined state

BUG=714373
R=japhet@chromium.org

Change-Id: Idf09c46a2dde8ce1107d8c8d1d414e5fa06987da
Reviewed-on: https://chromium-review.googlesource.com/758998
Commit-Queue: Jochen Eisinger <jochen@chromium.org>
Reviewed-by: Nate Chapin <japhet@chromium.org>
Cr-Commit-Position: refs/heads/master@{#515842}
1 file changed