Fix tap target consistency with link highlighting and hover/active

LayoutTests/compositing/gestures/resources/link-highlight-helper.js

 function createSquareCompositedHighlight(node)
 {
   return _createHighlight(node, "squaredHighlight highlightDiv composited");
 }
 
 function createCompositedHighlight(node)
 {
   return _createHighlight(node, "highlightDiv composited");
 }
 
@@ skipping 15 matching lines @@
   div.style.height = clientRect.height + "px";
 
   return div;
 }
 
 function useMockHighlight() {
   if (window.internals)
     internals.settings.setMockGestureTapHighlightsEnabled(true);
 }
 
+function testHighlightTarget(id) {
+    useMockHighlight();
+
+    var clientRect = document.getElementById('highlightTarget').getBoundingClientRect();
+    x = (clientRect.left + clientRect.right) / 2;
+    y = (clientRect.top + clientRect.bottom) / 2;
+    if (window.testRunner) {
+        testRunner.dumpAsTextWithPixelResults();
+        testRunner.waitUntilDone();
+    }
+
+    if (window.eventSender) {
+        eventSender.gestureTapDown(x, y, 30, 30);
+        eventSender.gestureShowPress(x, y, 30, 30);
+        window.setTimeout(function() { window.testRunner.notifyDone(); }, 0);
+    } else {
+        debug("This test requires eventSender");
+    }
+}