TextInputWidget: Work around Blink height miscalculation

Do a quick test to find what the difference between innerHeight and
scrollHeight of a textarea with no scrollbars is (should be 0, but
isn't on Blink), then apply the correction when setting height.

Bug: 71310
Change-Id: I92eb3afe89401e01d6531bcab793171939b192b0
Merge "TextInputWidget: Work around Blink height miscalculation"