[DevTools] New harness for inspector-protocol layout tests

third_party/WebKit/LayoutTests/inspector-protocol/stylesheet-tracking-restart.js

+(async function(testRunner) {
+  testRunner.log('This test checks that if style sheet is removed between two inspector launches it is not reported to frontend.');
+  var page = await testRunner.createPage();
+  var session = await page.createSession();
+  await session.evaluate(`
+    function createStyleSheet(textContent)
+    {
+        var styleElement = document.createElement('style');
+        styleElement.textContent = textContent;
+        document.head.appendChild(styleElement);
+        return styleElement;
+    }
+    window.styleElement1 = createStyleSheet('body.class1 { color: red; } \\n /*# sourceURL=foo.css */');
+    window.styleElement2 = createStyleSheet('body.class2 { color: green; } \\n /*# sourceURL=bar.css */');
+  `);
+  testRunner.log('\nRunning test');
+  testRunner.log('Opening front-end for the first time');
+  await runTest(session);
+  testRunner.log('Closing inspector.');
+  testRunner.log('\nRemoving style sheet.\n');
+  session.evaluate('setTimeout(() => document.head.removeChild(styleElement1), 0)');
+  await session.disconnect();
+  testRunner.log('Reopening inspector.');
+  session = await page.createSession();
+  testRunner.log('Running test');
+  testRunner.log('Opening front-end second time');
+  await runTest(session);
+  testRunner.completeTest();
+  async function runTest(session) {
+    var headersAdded = [];
+    session.protocol.CSS.onStyleSheetAdded(response => headersAdded.push(response.params.header));
+    var headersRemoved = [];
+    session.protocol.CSS.onStyleSheetRemoved(response => headersRemoved.push(response.params.styleSheetId));
+    testRunner.log('Enabling CSS domain.');
+    session.protocol.DOM.enable();
+    await session.protocol.CSS.enable();
+    var headers = {};
+    headersAdded.sort((a, b) => a.styleSheetId - b.styleSheetId);
+    for (var header of headersAdded) {
+      headers[header.styleSheetId] = header.sourceURL;
+      testRunner.log(' - style sheet added: ' + header.sourceURL);
+    }
+    headersRemoved.sort();
+    for (var styleSheetId of headersRemoved)
+      testRunner.log(' - style sheet removed: ' + headers[styleSheetId]);
+  }
+})