[Squad] Make style of inner editor not rely on LayoutObject.

Move custom style computation to TextControlInnerEditorElement and make
sure its style does not rely on the input host LayoutObject. Necessary
to be able to compute all elements' style in the RecalcStyle pass.

Bug: 813057
Change-Id: I823ca67b5ddaba08ce7adfc26a29f45f73d88b8f
Reviewed-on: https://chromium-review.googlesource.com/925701
Commit-Queue: Rune Lillesveen <futhark@chromium.org>
Reviewed-by: Kent Tamura <tkent@chromium.org>
Cr-Commit-Position: refs/heads/master@{#550589}
13 files changed