[DevTools] New harness for inspector-protocol layout tests

third_party/WebKit/LayoutTests/inspector-protocol/timeline/fetch-as-stream.js

+(async function(testRunner) {
+  let {page, session, dp} = await testRunner.startHTML(`
+    <style>
+    div#test {
+        display: none;
+        background-color: blue;
+        width: 100px;
+        height: 100px;
+    }
+    </style>
+    <div id='test'>
+    </div>
+  `, '');
+
+  var tracingHelper = (await testRunner.loadScript('../resources/tracing-test.js'))(testRunner, session);
+  tracingHelper.startTracingAndSaveAsStream(onStart);
+
+  function onStart() {
+    session.evaluate(`
+      (function performActions()
+      {
+          var element = document.getElementById('test');
+          element.style.display = 'block';
+          var unused = element.clientWidth;
+      })();
+    `).then(evalDone);
+  }
+
+  function evalDone() {
+    tracingHelper.stopTracingAndReturnStream(onStop);
+  }
+
+  function onStop(streamHandle) {
+    var data1;
+    tracingHelper.retrieveStream(streamHandle, null, null, onGotStream1);
+
+    function onGotStream1(data) {
+      data1 = data;
+      tracingHelper.retrieveStream(streamHandle, 0, 1000, onGotStream2);
+    }
+
+    function onGotStream2(data) {
+      if (data1 !== data)
+        testRunner.log('FAIL: got different data for cunked vs. non-chunked reads');
+      dp.IO.close({ handle: streamHandle }).then(onCloseDone);
+    }
+
+    function onCloseDone(response) {
+      testRunner.log('Error after legit close: ' + JSON.stringify(response.error));
+      dp.IO.read({ handle: streamHandle }).then(onReadAfterClose);
+    }
+
+    function onReadAfterClose(response) {
+      testRunner.log('Error after illegal read: ' + JSON.stringify(response.error));
+      dp.IO.close({ handle: streamHandle }).then(onCloseAfterClose);
+    }
+
+    function onCloseAfterClose(response) {
+      testRunner.log('Error after illegal close: ' + JSON.stringify(response.error));
+      var trace = JSON.parse(data1);
+      performEventsSanityCheck(trace['traceEvents']);
+      testRunner.log('Metadata: ' + typeof trace['metadata'] + (trace['metadata'] ? ', not null' : ''));
+      testRunner.completeTest();
+    }
+  }
+
+  function assertGreaterOrEqual(a, b, message) {
+    if (a >= b)
+      return;
+    testRunner.log(message + ' (' + a + ' < ' + b + ')');
+    testRunner.completeTest();
+  }
+
+  function performEventsSanityCheck(events) {
+    var phaseComplete = 0;
+
+    var knownEvents = {
+      'MessageLoop::PostTask': 0,
+      'FunctionCall': 0,
+      'UpdateLayoutTree': 0,
+      'Layout': 0
+    };
+
+    for (var i = 0; i < events.length; ++i) {
+      var event = events[i];
+      if (event.phase === 'X')
+        ++phaseComplete;
+      if (event.name in knownEvents)
+        ++knownEvents[event.name];
+    }
+    assertGreaterOrEqual(events.length, 10, 'Too few trace events recorded');
+    assertGreaterOrEqual(knownEvents['UpdateLayoutTree'], 1, 'Too few UpdateLayoutTree events');
+    assertGreaterOrEqual(knownEvents['Layout'], 1, 'Too few Layout events');
+    testRunner.log('Event sanity test done');
+  }
+})