[BlackBerry] Context menu cannot be invoked after doing text selection in landscape mode
https://bugs.webkit.org/show_bug.cgi?id=110860

Patch by Sean Wang <Xuewen.Wang@torchmobile.com.cn> on 2013-02-27
Reviewed by Yong Li.

PR 290248 Internally reviewed by Mike Fenton

Add a parameter to notify the webpage client which parts of selection have
changed in visual or in its selected DOM content. Refactor the selection details
parameter to platform repo.

The reason of this issue is that when javascript triggers webpage layout, the selection
will update its apperance event when the selected content is not changed. We want
to hide the context menu only when the selected content is changed not when only its
visual is changed.

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@144202 268f45cc-cd09-0410-ab3c-d52691b4dbfc