[gin] Fire observer after added when recording is in progress.

gin/v8_platform_unittest.cc

+// Copyright 2017 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 "gin/public/v8_platform.h"
+
+#include "base/trace_event/trace_event.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+class TestTraceStateObserver
+    : public NON_EXPORTED_BASE(v8::Platform::TraceStateObserver) {
+ public:
+  void OnTraceEnabled() final { ++enabled_; }
+  void OnTraceDisabled() final { ++disabled_; }
+  int Enabled() { return enabled_; }
+  int Disabled() { return disabled_; }
+
+ private:
+  int enabled_ = 0;
+  int disabled_ = 0;
+};
+
+namespace gin {
+
+TEST(V8PlatformTest, TraceStateObserverAPI) {
+  TestTraceStateObserver* test_observer = new TestTraceStateObserver();
+  ASSERT_EQ(0, test_observer->Enabled());
+  ASSERT_EQ(0, test_observer->Disabled());
+
+  V8Platform::Get()->AddTraceStateObserver(test_observer);
+  base::trace_event::TraceLog::GetInstance()->SetEnabled(
+      base::trace_event::TraceConfig("*", ""),
+      base::trace_event::TraceLog::RECORDING_MODE);
+  ASSERT_EQ(1, test_observer->Enabled());
+  ASSERT_EQ(0, test_observer->Disabled());
+  base::trace_event::TraceLog::GetInstance()->SetDisabled();
+  ASSERT_EQ(1, test_observer->Enabled());
+  ASSERT_EQ(1, test_observer->Disabled());
+
+  V8Platform::Get()->RemoveTraceStateObserver(test_observer);
+  base::trace_event::TraceLog::GetInstance()->SetEnabled(
+      base::trace_event::TraceConfig("*", ""),
+      base::trace_event::TraceLog::RECORDING_MODE);
+  base::trace_event::TraceLog::GetInstance()->SetDisabled();
+  ASSERT_EQ(1, test_observer->Enabled());
+  ASSERT_EQ(1, test_observer->Disabled());
+}
+
+TEST(V8PlatformTest, TraceStateObserverFired) {
+  TestTraceStateObserver* test_observer = new TestTraceStateObserver();
+  ASSERT_EQ(0, test_observer->Enabled());
+  ASSERT_EQ(0, test_observer->Disabled());
+
+  base::trace_event::TraceLog::GetInstance()->SetEnabled(
+      base::trace_event::TraceConfig("*", ""),
+      base::trace_event::TraceLog::RECORDING_MODE);
+  V8Platform::Get()->AddTraceStateObserver(test_observer);
+  ASSERT_EQ(1, test_observer->Enabled());
+  ASSERT_EQ(0, test_observer->Disabled());
+}
+
+}  // namespace gin