[WK2] WTR needs an implementation of setAsynchronousSpellCheckingEnabled

[WK2] WTR needs an implementation of setAsynchronousSpellCheckingEnabled
https://bugs.webkit.org/show_bug.cgi?id=81042

Reviewed by Enrica Casucci.

Source/WebKit2:

Expose WK2 setting to enable/disabled asynchronous spell checking.
It's used by WebKitTestRunner to reset the setting at the beginning
of the test.
WebKit2 ports might be interested in this setting if they are going
to enable this feature.

* Shared/WebPreferencesStore.h:
* UIProcess/API/C/WKPreferences.cpp:
(WKPreferencesSetAsynchronousSpellCheckingEnabled):
(WKPreferencesGetAsynchronousSpellCheckingEnabled):
* UIProcess/API/C/WKPreferences.h:
* WebProcess/InjectedBundle/API/c/WKBundle.cpp:
(WKBundleSetAsynchronousSpellCheckingEnabled):
* WebProcess/InjectedBundle/API/c/WKBundlePrivate.h:
* WebProcess/InjectedBundle/InjectedBundle.cpp:
(WebKit::InjectedBundle::setAsynchronousSpellCheckingEnabled):
* WebProcess/InjectedBundle/InjectedBundle.h:
* WebProcess/WebPage/WebPage.cpp:
(WebKit::WebPage::updatePreferences):

Tools:

Add setAsynchronousSpellCheckingEnabled implementation for
WebKitTestRunner to have the possibility to test asynchronous
spell checking implementation from bug 109577.

* WebKitTestRunner/InjectedBundle/Bindings/TestRunner.idl:
* WebKitTestRunner/InjectedBundle/TestRunner.cpp:
(WTR::TestRunner::setAsynchronousSpellCheckingEnabled):
* WebKitTestRunner/InjectedBundle/TestRunner.h:
* WebKitTestRunner/TestController.cpp:
(WTR::TestController::resetStateToConsistentValues):

LayoutTests:

Gardening of the asynchronous spell checking tests.

* platform/efl-wk2/TestExpectations:
* platform/efl/TestExpectations:
Some tests need to be skipped as they require features not
implemented for EFL yet (pasteboard, grammar checking, text replacement).

* platform/gtk-wk2/TestExpectations:
* platform/mac-wk2/TestExpectations:
* platform/qt-5.0-wk2/TestExpectations:
Skip asynchronous spell checking for GTK+, Mac, Qt unless
they implement TextChecker::requestCheckingOfText.

* platform/wk2/TestExpectations:
Remove asynchronous spell checking tests from global wk2's
as they are passing for EFL.

git-svn-id: https://svn.webkit.org/repository/webkit/trunk@144752 268f45cc-cd09-0410-ab3c-d52691b4dbfc