memory-infra: Start disentangling tracing from memory-infra

base/trace_event/memory_dump_manager.h

Index: base/trace_event/memory_dump_manager.h
diff --git a/base/trace_event/memory_dump_manager.h b/base/trace_event/memory_dump_manager.h
index 4e5f8a2f77d00afae4d3cffc59678a19421071e5..f0fdcf2ba3e3619af1b2c3dcc129b85b0b390990 100644
--- a/base/trace_event/memory_dump_manager.h
+++ b/base/trace_event/memory_dump_manager.h
@@ -39,6 +39,7 @@ class Thread;
 
 namespace trace_event {
 
+class MemoryTracingObserver;
 class MemoryDumpManagerDelegate;
 class MemoryDumpProvider;
 class MemoryDumpSessionState;
@@ -46,7 +47,7 @@ class MemoryDumpSessionState;
 // This is the interface exposed to the rest of the codebase to deal with
 // memory tracing. The main entry point for clients is represented by
 // RequestDumpPoint(). The extension by Un(RegisterDumpProvider).
-class BASE_EXPORT MemoryDumpManager : public TraceLog::EnabledStateObserver {
+class BASE_EXPORT MemoryDumpManager {
  public:
   static const char* const kTraceCategory;
   static const char* const kLogPrefix;
@@ -119,9 +120,9 @@ class BASE_EXPORT MemoryDumpManager : public TraceLog::EnabledStateObserver {
   void RequestGlobalDump(MemoryDumpType dump_type,
                          MemoryDumpLevelOfDetail level_of_detail);
 
-  // TraceLog::EnabledStateObserver implementation.
-  void OnTraceLogEnabled() override;
-  void OnTraceLogDisabled() override;
+  // XXX

[Primiano Tucci (use gerrit), 2017/04/21 10:10:26]

Can you add a comment explaining what Enable/Disable do? XXX is slightly too
cryptic :)

[hjd, 2017/04/21 11:51:57]

Done.

+  void Enable(const TraceConfig::MemoryDumpConfig&);
+  void Disable();
 
   // Enable heap profiling if kEnableHeapProfiling is specified.
   void EnableHeapProfilingIfNeeded();
@@ -167,6 +168,7 @@ class BASE_EXPORT MemoryDumpManager : public TraceLog::EnabledStateObserver {
   friend struct DefaultSingletonTraits<MemoryDumpManager>;
   friend class MemoryDumpManagerDelegate;
   friend class MemoryDumpManagerTest;
+  friend class MockMemoryDumpManager;

[Primiano Tucci (use gerrit), 2017/04/21 10:10:26]

doesn't seem to be used anymore?

[hjd, 2017/04/21 11:51:57]

Done.

   friend class memory_instrumentation::MemoryDumpManagerDelegateImplTest;
 
   // Holds the state of a process memory dump that needs to be carried over
@@ -230,7 +232,7 @@ class BASE_EXPORT MemoryDumpManager : public TraceLog::EnabledStateObserver {
   static const char* const kSystemAllocatorPoolName;
 
   MemoryDumpManager();
-  ~MemoryDumpManager() override;
+  virtual ~MemoryDumpManager();
 
   static void SetInstanceForTesting(MemoryDumpManager* instance);
   static uint32_t GetDumpsSumKb(const std::string&, const ProcessMemoryDump*);
@@ -284,6 +286,7 @@ class BASE_EXPORT MemoryDumpManager : public TraceLog::EnabledStateObserver {
       strict_thread_check_blacklist_;
 
   std::unique_ptr<MemoryDumpManagerDelegate> delegate_;
+  std::unique_ptr<MemoryTracingObserver> trace_log_observer_;

[Primiano Tucci (use gerrit), 2017/04/21 10:10:26]

I'd just call it tracing_observer_ to keep it consistent with the class name.

[hjd, 2017/04/21 11:51:57]

Done.

 
   // Protects from concurrent accesses to the |dump_providers_*| and |delegate_|
   // to guard against disabling logging while dumping on another thread.