https://bugs.webkit.org/show_bug.cgi?id=50860
<rdar://problem/8660807>

The backing stores used for painting the popup menu items were only as
wide as the widest option title, but the popup window that we create is
at least as wide as the <select> element. This adjusts the backing
stores to be at least as wide as the <select>, as well.

Reviewed by Sam Weinig.

* UIProcess/win/WebPopupMenuProxyWin.cpp:
(WebKit::WebPopupMenuProxyWin::paint):
Paint using the width of the backing store.

* WebProcess/WebCoreSupport/WebPopupMenu.cpp:
(WebKit::WebPopupMenu::show):
Pass the page coordinates of the <select> element to
setUpPlatformData().

* WebProcess/WebCoreSupport/WebPopupMenu.h:
Added new parameter to setUpPlatformData().

* WebProcess/WebCoreSupport/mac/WebPopupMenuMac.mm:
(WebKit::WebPopupMenu::setUpPlatformData):
Ditto.

* WebProcess/WebCoreSupport/qt/WebPopupMenuQt.cpp:
(WebKit::WebPopupMenu::setUpPlatformData):
Ditto.

* WebProcess/WebCoreSupport/win/WebPopupMenuWin.cpp:
(WebKit::WebPopupMenu::setUpPlatformData):
Fixed a typo in a comment. Adjust the backing store size to be at least
as wide as the <select> element, and use that width when painting the
items to the backing store.

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@73852 268f45cc-cd09-0410-ab3c-d52691b4dbfc