remove set oopif mouse capture on text selection

In crrev.com/588115 introduced capture mouse events to widget during
text selection; and a later change crrev.com/599408 make subframe
widgets capture mouse events on MouseDown, which follows the behavior
without OOPIF.
Since we are captureing mouse events on MouseDown and release the
capture on MouseUp, we don't need to treat the text selection case
special.

Bug: 647378
Change-Id: I207777d16e11e069fb1ab60579d45324cb5b06c4
Reviewed-on: https://chromium-review.googlesource.com/c/1308606
Reviewed-by: Ken Buchanan <kenrb@chromium.org>
Reviewed-by: Xiaocheng Hu <xiaochengh@chromium.org>
Reviewed-by: Mustaq Ahmed <mustaq@chromium.org>
Commit-Queue: Ella Ge <eirage@chromium.org>
Cr-Commit-Position: refs/heads/master@{#606573}
2 files changed