implement SetWatchEvent and WaitForEvent for trace-based-tests

chrome/test/base/tracing_browsertest.cc

+// Copyright (c) 2012 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "chrome/test/base/tracing.h"
+
+#include "base/debug/trace_event.h"
+#include "base/message_loop.h"
+#include "base/run_loop.h"
+#include "chrome/test/base/in_process_browser_test.h"
+#include "chrome/test/base/ui_test_utils.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace {
+
+using tracing::BeginTracingWithWatch;
+using tracing::WaitForWatchEvent;
+using tracing::EndTracing;
+
+const char* g_category = "test_tracing";
+const char* g_event = "TheEvent";
+
+class TracingBrowserTest : public InProcessBrowserTest {
+};
+
+void AddEvents(int num) {
+  for (int i = 0; i < num; ++i)
+    TRACE_EVENT_INSTANT0(g_category, g_event);
+}
+
+IN_PROC_BROWSER_TEST_F(TracingBrowserTest, BeginTracingWithWatch) {
+  base::TimeDelta no_timeout;
+  base::TimeDelta short_timeout = base::TimeDelta::FromMilliseconds(5);
+  std::string json_events;
+
+  // One event before wait.
+  ASSERT_TRUE(BeginTracingWithWatch(g_category, g_category, g_event, 1));
+  AddEvents(1);
+  EXPECT_TRUE(WaitForWatchEvent(no_timeout));
+  ASSERT_TRUE(EndTracing(&json_events));
+
+  // One event after wait.
+  ASSERT_TRUE(BeginTracingWithWatch(g_category, g_category, g_event, 1));
+  MessageLoop::current()->PostTask(FROM_HERE, base::Bind(&AddEvents, 1));
+  EXPECT_TRUE(WaitForWatchEvent(no_timeout));
+  ASSERT_TRUE(EndTracing(&json_events));
+
+  // Not enough events timeout.
+  ASSERT_TRUE(BeginTracingWithWatch(g_category, g_category, g_event, 2));
+  AddEvents(1);
+  EXPECT_FALSE(WaitForWatchEvent(short_timeout));
+  ASSERT_TRUE(EndTracing(&json_events));
+
+  // Multi event before wait.
+  ASSERT_TRUE(BeginTracingWithWatch(g_category, g_category, g_event, 5));
+  AddEvents(5);
+  EXPECT_TRUE(WaitForWatchEvent(no_timeout));
+  ASSERT_TRUE(EndTracing(&json_events));
+
+  // Multi event after wait.
+  ASSERT_TRUE(BeginTracingWithWatch(g_category, g_category, g_event, 5));
+  MessageLoop::current()->PostTask(FROM_HERE, base::Bind(&AddEvents, 5));
+  EXPECT_TRUE(WaitForWatchEvent(no_timeout));
+  ASSERT_TRUE(EndTracing(&json_events));
+
+  // Child process events from same process.
+  GURL url1("chrome://tracing");
+  ASSERT_TRUE(BeginTracingWithWatch(g_category, g_category,
+                                    "RenderViewImpl::OnNavigate", 2));
+  ui_test_utils::NavigateToURL(browser(), url1);
+  ui_test_utils::NavigateToURL(browser(), url1);
+  EXPECT_TRUE(WaitForWatchEvent(no_timeout));
+  ASSERT_TRUE(EndTracing(&json_events));
+
+  // Child process events from different processes.
+  GURL url2("about:blank");
+  ASSERT_TRUE(BeginTracingWithWatch(g_category, g_category,
+                                    "RenderViewImpl::OnNavigate", 2));
+  // Open two tabs to different URLs to encourage two separate renderer
+  // processes. Each will fire an event that will be counted towards the total.
+  ui_test_utils::NavigateToURL(browser(), url1);
+  ui_test_utils::NavigateToURLWithDisposition(browser(), url2,
+      NEW_FOREGROUND_TAB, ui_test_utils::BROWSER_TEST_WAIT_FOR_NAVIGATION);
+  EXPECT_TRUE(WaitForWatchEvent(no_timeout));
+  ASSERT_TRUE(EndTracing(&json_events));
+}
+
+}  // namespace