memory-infra: Start disentangling tracing from memory-infra

base/trace_event/trace_log.h

Index: base/trace_event/trace_log.h
diff --git a/base/trace_event/trace_log.h b/base/trace_event/trace_log.h
index 88b6e588e406e70c064ebaea09918033354e15fc..c9e0a6175d28d9db8cb698b83bb982ed6163cb91 100644
--- a/base/trace_event/trace_log.h
+++ b/base/trace_event/trace_log.h
@@ -90,7 +90,7 @@ class BASE_EXPORT TraceLog : public MemoryDumpProvider {
 
   // Returns true if TraceLog is enabled on recording mode.
   // Note: Returns false even if FILTERING_MODE is enabled.
-  bool IsEnabled() { return enabled_modes_ & RECORDING_MODE; }
+  virtual bool IsEnabled();

[hjd, 2017/04/13 14:16:59]

So I can mock.

 
   // Returns a bitmap of enabled modes from TraceLog::Mode.
   uint8_t enabled_modes() { return enabled_modes_; }
@@ -123,8 +123,8 @@ class BASE_EXPORT TraceLog : public MemoryDumpProvider {
     // TraceLog::IsEnabled() is false at this point.
     virtual void OnTraceLogDisabled() = 0;
   };
-  void AddEnabledStateObserver(EnabledStateObserver* listener);
-  void RemoveEnabledStateObserver(EnabledStateObserver* listener);
+  virtual void AddEnabledStateObserver(EnabledStateObserver* listener);
+  virtual void RemoveEnabledStateObserver(EnabledStateObserver* listener);

[hjd, 2017/04/13 14:16:59]

So I can mock.

   bool HasEnabledStateObserver(EnabledStateObserver* listener) const;
 
   // Asynchronous enabled state listeners. When tracing is enabled or disabled,
@@ -345,6 +345,7 @@ class BASE_EXPORT TraceLog : public MemoryDumpProvider {
                            ConvertTraceConfigToInternalOptions);
   FRIEND_TEST_ALL_PREFIXES(TraceEventTestFixture,
                            TraceRecordAsMuchAsPossibleMode);
+  friend class MockTraceLog;
 
   // This allows constructor and destructor to be private and usable only
   // by the Singleton class.