commit a6dadbcc9839a6888be4f5f554ab9e953c621d16
author Yoshifumi Inoue <yosin@chromium.org> Fri Oct 30 00:59:33 2020
committer Commit Bot <commit-bot@chromium.org> Fri Oct 30 00:59:33 2020
tree 4ea2e830aa6d677b4ee441adc55a4f46cf3ddb2b
parent b4a697e36b1613bc9e30c8650d7d5a833ce6597d

Make InputMethodController::GetImeTextSpansAroundPosition() to take Position

This patch changes |GetImeTextSpansAroundPosition()| to take |Position|
instead of offset in root editable element to avoid using
|PalinTextRange|, to avoid redundant calculation for improving
performance.

Note: Even if this change, large content editable is still slow due by
|PlainTextRange| uses |TextIterator| to collect text from root editable
element and map DOM position to offset for every frame or 16ms.

For every frame, we call
 * InputMethodController::TextInputInfo()
     - PlainText() for root editable elements
     - TextIterator for end of selection
     - TextIterator for end of composition
 * InputMethodController::GetSelectionOffsets()
     - TextIterator for end of selection
Mapping time depends of number of DOM node between start of root
editable and position. When selection or IME composition are far from
start of root editable element, mapping takes time.

Bug: 892513
Change-Id: Id2f6694e3fee2b23b697a1aaf1830cd0d897d61a
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2507129
Commit-Queue: Yoshifumi Inoue <yosin@chromium.org>
Auto-Submit: Yoshifumi Inoue <yosin@chromium.org>
Reviewed-by: Koji Ishii <kojii@chromium.org>
Cr-Commit-Position: refs/heads/master@{#822460}