Add support for touch-action: pinch-zoom.

third_party/WebKit/LayoutTests/imported/wpt_automation/pointerevents/pointerevent_common_input.js

Index: third_party/WebKit/LayoutTests/imported/wpt_automation/pointerevents/pointerevent_common_input.js
diff --git a/third_party/WebKit/LayoutTests/imported/wpt_automation/pointerevents/pointerevent_common_input.js b/third_party/WebKit/LayoutTests/imported/wpt_automation/pointerevents/pointerevent_common_input.js
index 2d1456db32e6873e4c4eb03b288eef60cfd25e95..773c9d88caa2dcabf1fcd72121eb070b488f35ca 100644
--- a/third_party/WebKit/LayoutTests/imported/wpt_automation/pointerevents/pointerevent_common_input.js
+++ b/third_party/WebKit/LayoutTests/imported/wpt_automation/pointerevents/pointerevent_common_input.js
@@ -138,6 +138,21 @@ function touchScrollInTarget(targetSelector, direction) {
   });
 }
 
+function pinchZoomInTarget(targetSelector, scale) {
+  return new Promise(function(resolve, reject) {
+    if (window.chrome && chrome.gpuBenchmarking) {
+      scrollPageIfNeeded(targetSelector, document);
+      var target = document.querySelector(targetSelector);
+      var targetRect = target.getBoundingClientRect();
+      chrome.gpuBenchmarking.pinchBy(scale, targetRect.left + (targetRect.width/2), targetRect.top + (targetRect.height/2), function() {
+        resolve();
+      });
+    } else {
+      reject();
+    }
+  });
+}
+
 // Pen inputs.
 function penMoveToDocument() {
   return new Promise(function(resolve, reject) {