chore: unflake tracing test (#1822)

Author: yury-s

playwright/src/test/java/com/microsoft/playwright/TestChromiumTracing.java

@@ -57,14 +57,21 @@ void shouldCreateDirectoriesAsNeeded(@TempDir Path tempDir) {
     }
   }
 
+  private static void rafraf(Page page) {
+    int count = 2;
+    for (int i = 0; i < count; i++) {
+      page.evaluate("() => new Promise(f => requestAnimationFrame(() => requestAnimationFrame(f)))");
+    }
+  }
+
   @Test
   void shouldRunWithCustomCategoriesIfProvided(@TempDir Path tempDir) throws IOException {
     try (Page page = browser.newPage()) {
       Path outputTraceFile = tempDir.resolve("trace.json");
       browser.startTracing(page, new Browser.StartTracingOptions()
         .setPath(outputTraceFile)
         .setCategories(asList("disabled-by-default-cc.debug")));
-      page.evaluate("() => 1 + 1");
+      rafraf(page);
       browser.stopTracing();
       try (FileReader fileReader = new FileReader(outputTraceFile.toFile())) {
         JsonObject traceJson = new Gson().fromJson(fileReader, JsonObject.class);
@@ -75,7 +82,7 @@ void shouldRunWithCustomCategoriesIfProvided(@TempDir Path tempDir) throws IOExc
         boolean hasTraceEvents = traceJson.getAsJsonArray("traceEvents").asList().stream()
             .anyMatch(event -> {
               JsonObject eventObj = (JsonObject) event;
-              return eventObj.has("cat") && 
+              return eventObj.has("cat") &&
                 eventObj.get("cat").getAsString().equals("disabled-by-default-cc.debug");
             });
         assertTrue(hasTraceConfig || hasTraceEvents);