Source/WebCore: preventDefault() in a mousedown in a subframe should not

Source/WebCore: preventDefault() in a mousedown in a subframe should not
prevent the scrollbar from handling mouse movements if the
cursor leaves the subframe.
https://bugs.webkit.org/show_bug.cgi?id=73097

Reviewed by Darin Adler.

Test: fast/events/scroll-div-with-prevent-default-in-subframe.html

* page/EventHandler.cpp:
(WebCore::EventHandler::handleMousePressEvent):

LayoutTests: Test for https://bugs.webkit.org/show_bug.cgi?id=73097.
Test adapted from repro case provided by zacklloyd@google.com.

Reviewed by Darin Adler.

* fast/events/resources/subframe-with-scrollable-div.html: Added.
* fast/events/scroll-div-with-prevent-default-in-subframe-expected.txt: Added.
* fast/events/scroll-div-with-prevent-default-in-subframe.html: Added.

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@106476 268f45cc-cd09-0410-ab3c-d52691b4dbfc