[Qt] Implement tap feedback respecting -webkit-tap-highlight-color

[Qt] Implement tap feedback respecting -webkit-tap-highlight-color
https://bugs.webkit.org/show_bug.cgi?id=76914

Reviewed by Simon Hausmann.

.:

Add a manual test.

* ManualTests/qt/tap-highlighting.html: Added.

Source/WebCore:

Implement highlighting of dom nodes with a rounded rect, respecting
the color of -webkit-tap-highlight-color and any transform applied
to the element.

Tested with manual test.

* Target.pri:
* page/GestureTapHighlighter.cpp: Added.
(WebCore::GestureTapHighlighter::pathForNodeHighlight):
* page/GestureTapHighlighter.h: Added.

Source/WebKit2:

Implement tap highlighting for Qt. When a touch press is issued,
which is not handled by the web page, then we highlight any
activatable node below. In all otehr cases, we hide any highlights.

The highlighting itself is painted on an accelerated PageOverlay,
on the web process side.

* Target.pri:
* UIProcess/WebPageProxy.cpp:
(WebKit::WebPageProxy::handlePotentialActivation):
* UIProcess/WebPageProxy.h:
* UIProcess/qt/QtTapGestureRecognizer.cpp:
(WebKit::QtTapGestureRecognizer::recognize):
* UIProcess/qt/QtWebPageEventHandler.cpp:
(QtWebPageEventHandler::handlePotentialSingleTapEvent):
* UIProcess/qt/QtWebPageEventHandler.h:
* WebProcess/WebPage/TapHighlightController.cpp: Added.
(WebKit::TapHighlightController::TapHighlightController):
(WebKit::TapHighlightController::~TapHighlightController):
(WebKit::TapHighlightController::highlight):
(WebKit::TapHighlightController::hideHighlight):
(WebKit::TapHighlightController::pageOverlayDestroyed):
(WebKit::TapHighlightController::willMoveToWebPage):
(WebKit::TapHighlightController::didMoveToWebPage):
(WebKit::highlightColor):
(WebKit::TapHighlightController::drawRect):
(WebKit::TapHighlightController::mouseEvent):
* WebProcess/WebPage/TapHighlightController.h: Added.
* WebProcess/WebPage/WebPage.cpp:
(WebKit::WebPage::WebPage):
(WebKit::WebPage::highlightPotentialActivation):
* WebProcess/WebPage/WebPage.h:
(WebKit::WebPage::tapHighlightController):
* WebProcess/WebPage/WebPage.messages.in:

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@105893 268f45cc-cd09-0410-ab3c-d52691b4dbfc