test: disable flaky firefox tests (#1912)

Author: aslushnikov

test/fixtures.spec.js

@@ -124,7 +124,10 @@ describe('Fixtures', function() {
       // TODO: ideally, we would expect the SIGKILL on the browser from
       // force kill, but that's racy with sending two signals.
     });
-    it.slow()('should kill the browser on SIGTERM + SIGINT', async state => {
+    // TODO: flaky!
+    // - firefox: https://github.com/microsoft/playwright/pull/1911/checks?check_run_id=607148951
+    // - chromium: https://travis-ci.com/github/microsoft/playwright/builds/161356178
+    it.slow().fail((FFOX || CHROMIUM) && LINUX)('should kill the browser on SIGTERM + SIGINT', async state => {
       const result = await testSignal(state, child => {
         process.kill(child.pid, 'SIGTERM');
         process.kill(child.pid, 'SIGINT');

test/mouse.spec.js

@@ -15,7 +15,7 @@
  * limitations under the License.
  */
 
-const {FFOX, CHROMIUM, WEBKIT, MAC} = require('./utils').testOptions(browserType);
+const {FFOX, CHROMIUM, WEBKIT, MAC, WIN} = require('./utils').testOptions(browserType);
 
 function dimensions() {
   const rect = document.querySelector('textarea').getBoundingClientRect();
@@ -28,7 +28,8 @@ function dimensions() {
 }
 
 describe('Mouse', function() {
-  it('should click the document', async({page, server}) => {
+  // Occasionally times out on FFOX on Windows: https://github.com/microsoft/playwright/pull/1911/checks?check_run_id=607149016
+  it.fail(FFOX && WIN)('should click the document', async({page, server}) => {
     await page.evaluate(() => {
       window.clickPromise = new Promise(resolve => {
         document.addEventListener('click', event => {