REGRESSION (WebKit2): Tab keys no longer observe Full Keyboard Access
        https://bugs.webkit.org/show_bug.cgi?id=55633
        <rdar://problem/8963023>

        * WebKit2.xcodeproj/project.pbxproj:
        * WebProcess/mac/FullKeyboardAccessWatcher.h: Added.
        * WebProcess/mac/FullKeyboardAccessWatcher.mm: Added.
        (-[FullKeyboardAccessWatcher retrieveKeyboardUIModeFromPreferences:]):
        (-[FullKeyboardAccessWatcher init]):
        (+[FullKeyboardAccessWatcher fullKeyboardAccessEnabled]):
        Get the current state of full keyboard access, listening for change notifications.

        * WebProcess/WebProcess.h:  Added fullKeyboardAccessEnabled().

        * WebProcess/WebProcess.cpp: (WebKit::WebProcess::fullKeyboardAccessEnabled):
        WebKit1 also doesn't implement this on platforms other than Mac.

        * WebProcess/mac/WebProcessMac.mm: (WebKit::WebProcess::fullKeyboardAccessEnabled):
        Just ask FullKeyboardAccessWatcher.

        * WebProcess/WebCoreSupport/WebChromeClient.cpp: (WebKit::WebChromeClient::keyboardUIMode):
        * WebProcess/WebCoreSupport/WebChromeClient.h:
        Added keyboardUIMode(), removed tabsToLinks().

        * WebProcess/WebPage/WebPage.cpp: (WebKit::WebPage::keyboardUIMode):
        * WebProcess/WebPage/WebPage.h:
        Generate keyboard UI mode from tabToLinks preference and current state of FKA.



git-svn-id: http://svn.webkit.org/repository/webkit/trunk@80279 268f45cc-cd09-0410-ab3c-d52691b4dbfc