AX: [ATK] Crash getting the orientation of a MenuListOption after the MenuList was removed from the document
https://bugs.webkit.org/show_bug.cgi?id=138727

Reviewed by Chris Fleizach.

Source/WebCore:

AccessibilityMenuListOption::elementRect() returns the value of the
grandparent MenuList, asserting that the grandparent exists with that
role. But it is possible to have an existing MenuListOption and remove
the element which had been backing that MenuList from the document.
Adding null checks prior to the assertions prevents our crashing if the
parent or grandparent was removed.

Test: platform/gtk/accessibility/combobox-descendants-orientation-crash.html

* accessibility/AccessibilityMenuListOption.cpp:
(WebCore::AccessibilityMenuListOption::elementRect):

LayoutTests:

* platform/gtk/accessibility/combobox-descendants-orientation-crash-expected.txt: Added.
* platform/gtk/accessibility/combobox-descendants-orientation-crash.html: Added.


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@176254 268f45cc-cd09-0410-ab3c-d52691b4dbfc
[GTK] Mesa build fails over llvm-3.5
https://bugs.webkit.org/show_bug.cgi?id=138825

Reviewed by Gustavo Noronha Silva.

OwningPtr.h have been removed in llvm-3.5. Instread we should use std::unique_ptr for mesa build.

* gtk/jhbuild.modules:
* gtk/patches/mesa-gallivm-Fix-build-after-LLVM-commit-211259.patch: Added.


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@176255 268f45cc-cd09-0410-ab3c-d52691b4dbfc