Initial touch-action main thread implementation

Source/web/tests/data/touch-action-tests.js

+// Disable compositor hit testing
+document.addEventListener('touchstart', function() {});
+
+window.addEventListener('load', function() {
+  // Create any shadow DOM nodes requested by the test.
+  var shadowTrees = document.querySelectorAll('[make-shadow-dom]');
+  if (shadowTrees.length > 0 && !HTMLElement.prototype.createShadowRoot) {
+    document.body.innerHTML = 'ERROR: Shadow DOM not supported!';
+    return;
+  }
+  for (var i = 0; i < shadowTrees.length; i++) {
+    var tree = shadowTrees[i];
+    var host = tree.previousElementSibling;
+    if (!host.hasAttribute('shadow-host')) {
+      document.body.innerHTML = 'ERROR: make-shadow-dom node must follow a shadow-host node';
+      return;
+    }
+    tree.parentElement.removeChild(tree);
+    var shadowRoot = host.createShadowRoot();
+    shadowRoot.applyAuthorStyles = true;
+    shadowRoot.appendChild(tree);
+  }
+});
+
+/*
+ * Visualization of hit test locations for manual testing.
+ * To be invoked manually (so it doesn't intefere with testing).
+ */
+function addMarker(x, y)
+{
+    const kMarkerSize = 6;
+    var marker = document.createElement('div');
+    marker.className = 'marker';
+    marker.style.top = (y - kMarkerSize/2) + 'px';
+    marker.style.left = (x - kMarkerSize/2) + 'px';
+    document.body.appendChild(marker);
+}
+
+function addMarkers()
+{
+  var tests = document.querySelectorAll('[expected-action]');
+  for (var i = 0; i < tests.length; i++) {
+    var r = tests[i].getClientRects()[0];
+    addMarker(r.left, r.top);
+    addMarker(r.right - 1, r.bottom - 1);
+    addMarker(r.left + r.width / 2, r.top + r.height / 2);
+  }
+}