[memory-infra] Add support for polling memory totals in MemoryDumpManager

base/trace_event/memory_dump_session_state.h

 // Copyright 2015 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.
 
 #ifndef BASE_TRACE_EVENT_MEMORY_DUMP_SESSION_STATE_H_
 #define BASE_TRACE_EVENT_MEMORY_DUMP_SESSION_STATE_H_
 
 #include <memory>
 
 #include "base/base_export.h"
@@ skipping 28 matching lines @@
 
   void SetTypeNameDeduplicator(
       std::unique_ptr<TypeNameDeduplicator> type_name_deduplicator);
 
   const TraceConfig::MemoryDumpConfig& memory_dump_config() const {
     return memory_dump_config_;
   }
 
   void SetMemoryDumpConfig(const TraceConfig::MemoryDumpConfig& config);
 
+  bool is_polling_enabled() { return is_polling_enabled_; }
+
  private:
   friend class RefCountedThreadSafe<MemoryDumpSessionState>;
   ~MemoryDumpSessionState();
 
   // Deduplicates backtraces in heap dumps so they can be written once when the
   // trace is finalized.
   std::unique_ptr<StackFrameDeduplicator> stack_frame_deduplicator_;
 
   // Deduplicates type names in heap dumps so they can be written once when the
   // trace is finalized.
   std::unique_ptr<TypeNameDeduplicator> type_name_deduplicator_;
 
   // The memory dump config, copied at the time when the tracing session was
   // started.
   TraceConfig::MemoryDumpConfig memory_dump_config_;
+
+  // True if memory polling is enabled by the config in the tracing session.
+  bool is_polling_enabled_;
 };
 
 }  // namespace trace_event
 }  // namespace base
 
 #endif  // BASE_TRACE_EVENT_MEMORY_DUMP_SESSION_STATE_H_