[Qt] PluginsX11: exposedRect offset is applied twice when painting windowless
https://bugs.webkit.org/show_bug.cgi?id=114020

Reviewed by Simon Hausmann.

Both XGetImage and QPainter::drawImage would apply the offset.
Since the XImage will only contain the exposed rect, no need to specify
the source rect to drawImage.

* plugins/qt/PluginViewQt.cpp:
(WebCore::PluginView::paintUsingXPixmap):


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@147737 268f45cc-cd09-0410-ab3c-d52691b4dbfc