Add OnBeforeTraceLogDisabled notification to EnabledStateObserver

base/trace_event/trace_event_unittest.cc

Index: base/trace_event/trace_event_unittest.cc
diff --git a/base/trace_event/trace_event_unittest.cc b/base/trace_event/trace_event_unittest.cc
index ace98fdf6e837c679a93cb87e3eb099f4dea6c6c..ac7983426c960d5ec6efaf2b2b923f6d1b0e5cc8 100644
--- a/base/trace_event/trace_event_unittest.cc
+++ b/base/trace_event/trace_event_unittest.cc
@@ -1092,6 +1092,7 @@ class MockEnabledStateChangedObserver :
  public:
   MOCK_METHOD0(OnTraceLogEnabled, void());
   MOCK_METHOD0(OnTraceLogDisabled, void());
+  MOCK_METHOD0(OnBeforeTraceLogDisabled, void());
 };
 
 TEST_F(TraceEventTestFixture, EnabledObserverFiresOnEnable) {
@@ -1119,6 +1120,7 @@ TEST_F(TraceEventTestFixture, EnabledObserverDoesntFireOnSecondEnable) {
 
   EXPECT_CALL(observer, OnTraceLogEnabled())
       .Times(0);
+  EXPECT_CALL(observer, OnBeforeTraceLogDisabled()).Times(0);
   EXPECT_CALL(observer, OnTraceLogDisabled())
       .Times(0);
   TraceLog::GetInstance()->SetEnabled(TraceConfig(kRecordAllCategoryFilter, ""),
@@ -1142,6 +1144,7 @@ TEST_F(TraceEventTestFixture, EnabledObserverFiresOnFirstDisable) {
 
   EXPECT_CALL(observer, OnTraceLogEnabled())
       .Times(0);
+  EXPECT_CALL(observer, OnBeforeTraceLogDisabled()).Times(1);
   EXPECT_CALL(observer, OnTraceLogDisabled())
       .Times(1);
   TraceLog::GetInstance()->SetDisabled();
@@ -1159,6 +1162,7 @@ TEST_F(TraceEventTestFixture, EnabledObserverFiresOnDisable) {
   MockEnabledStateChangedObserver observer;
   TraceLog::GetInstance()->AddEnabledStateObserver(&observer);
 
+  EXPECT_CALL(observer, OnBeforeTraceLogDisabled()).Times(1);
   EXPECT_CALL(observer, OnTraceLogDisabled())
       .Times(1);
   TraceLog::GetInstance()->SetDisabled();
@@ -1180,6 +1184,10 @@ class AfterStateChangeEnabledStateObserver
     EXPECT_TRUE(TraceLog::GetInstance()->IsEnabled());
   }
 
+  void OnBeforeTraceLogDisabled() override {
+    EXPECT_TRUE(TraceLog::GetInstance()->IsEnabled());
+  }
+
   void OnTraceLogDisabled() override {
     EXPECT_FALSE(TraceLog::GetInstance()->IsEnabled());
   }
@@ -1228,6 +1236,28 @@ TEST_F(TraceEventTestFixture, SelfRemovingObserver) {
   EXPECT_EQ(0u, TraceLog::GetInstance()->GetObserverCountForTest());
 }
 
+// Tests that an event can be fired during OnBeforeTraceLogDisabled.
+class EventWritingStateObserver : public TraceLog::EnabledStateObserver {
+ public:
+  // TraceLog::EnabledStateObserver overrides:
+  void OnTraceLogEnabled() override {}
+  void OnTraceLogDisabled() override {}
+  void OnBeforeTraceLogDisabled() override {
+    TRACE_EVENT_INSTANT0("x", "y", TRACE_EVENT_SCOPE_THREAD);
+  }
+};
+
+TEST_F(TraceEventTestFixture, WriteTraceEventOnBeforeTraceLogDisabled) {
+  EventWritingStateObserver observer;
+  TraceLog::GetInstance()->AddEnabledStateObserver(&observer);
+
+  TraceLog::GetInstance()->SetEnabled(TraceConfig(kRecordAllCategoryFilter, ""),
+                                      TraceLog::RECORDING_MODE);
+  EndTraceAndFlush();
+  TraceLog::GetInstance()->RemoveEnabledStateObserver(&observer);
+  EXPECT_TRUE(FindNamePhase("y", "I"));
+}
+
 bool IsNewTrace() {
   bool is_new_trace;
   TRACE_EVENT_IS_NEW_TRACE(&is_new_trace);