https://bugs.webkit.org/show_bug.cgi?id=87408
PR #153056 / MKS_3674963

Reviewed by Adam Treat.
Patch by Antonio Gomes <agomes@rim.com>

Also informally reviewed by Mike Fenton.

If we are not rotating and we've started a viewport resize with
the Render tree in dirty state (i.e. it needs layout), lets
reset the needsLayout flag for now but set our own 'needsLayout'.

Reason: calls like ScrollView::setFixedLayoutSize can trigger a layout
if the render tree needs it. We want to avoid it till the viewport resize
is actually done (i.e. ScrollView::setViewportSize gets called
further down the method) so we do not get render artifacts.

Since our WebPage::setViewportSize calls rely on async Virtual
Keyboard responses, we were getting it called with the render
tree sometimes in a dirty state, sometimes not. It was flaky!
Patch ensures a clear render tree state, and sets it as dirty
afterwards as needed, so layout happens at the proper time.

* Api/WebPage.cpp:
(BlackBerry::WebKit::WebPagePrivate::setViewportSize):

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@118405 268f45cc-cd09-0410-ab3c-d52691b4dbfc