Merge 125757 - Prevent showing suggestions when right-clicking a selection range.

Merge 125757 - Prevent showing suggestions when right-clicking a selection range.
https://bugs.webkit.org/show_bug.cgi?id=94189

Reviewed by Hajime Morita.

To emulate Safari, my r120810 changes selection when right-clicking a misspelled
word. Unfortunately, this change somehow uses VisibleSelection::isCaretOrRange
and it changes the existing selection when right-clicking a selection which
includes a misspelled word. This change uses VisibleSelection::isCaret to
prevent showing suggestions when right-clicking a selection range. (Neither does
Safari show suggestions when there is a selection range.)

* src/ContextMenuClientImpl.cpp:
(WebKit::ContextMenuClientImpl::getCustomMenuFromDefaultItems):


TBR=hbono@chromium.org
Committed: https://trac.webkit.org/changeset/126725