[PointerLock] Add null check before dispatching click event

third_party/WebKit/LayoutTests/external/wpt_automation/pointerlock/pointerlock_common_input.js

+// This file contains the commonly used functions in pointerlock tests.
+
+const boundaryOffset = 2;
+
+function scrollPageIfNeeded(targetSelector, targetDocument) {
+  const target = targetDocument.querySelector(targetSelector);
+  const targetRect = target.getBoundingClientRect();
+  if (targetRect.top < 0 || targetRect.left < 0 || targetRect.bottom > window.innerHeight || targetRect.right > window.innerWidth)
+    window.scrollTo(targetRect.left, targetRect.top);
+}
+
+function mouseClickInTarget(targetSelector, targetFrame, button) {
+  let targetDocument = document;
+  let frameLeft = 0;
+  let frameTop = 0;
+  if (button === undefined) {
+    button = 'left';
+  }
+  if (targetFrame !== undefined) {
+    targetDocument = targetFrame.contentDocument;
+    const frameRect = targetFrame.getBoundingClientRect();
+    frameLeft = frameRect.left;
+    frameTop = frameRect.top;
+  }
+  return new Promise(function(resolve, reject) {
+    if (window.chrome && chrome.gpuBenchmarking) {
+      scrollPageIfNeeded(targetSelector, targetDocument);
+      const target = targetDocument.querySelector(targetSelector);
+      const targetRect = target.getBoundingClientRect();
+      const xPosition = frameLeft + targetRect.left + boundaryOffset;
+      const yPosition = frameTop + targetRect.top + boundaryOffset;
+      chrome.gpuBenchmarking.pointerActionSequence(
+          [{
+            source: 'mouse',
+            actions: [
+              {name: 'pointerMove', x: xPosition, y: yPosition},
+              {name: 'pointerDown', x: xPosition, y: yPosition, button: button},
+              {name: 'pointerUp', button: button}
+            ]
+          }],
+          resolve);
+    } else {
+      reject();
+    }
+  });
+}
+
+{
+  const pointerlock_automation = async_test("PointerLock Automation");
+  // Defined in every test and should return a promise that gets resolved when input is finished.
+  inject_input().then(function() {
+    pointerlock_automation.done();
+  });
+}