[tracing] Switch to new heap dump format.

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 <set>
 
@@ skipping 11 matching lines @@
     : public RefCountedThreadSafe<MemoryDumpSessionState> {
  public:
   MemoryDumpSessionState();
 
   // Returns the stack frame deduplicator that should be used by memory dump
   // providers when doing a heap dump.
   StackFrameDeduplicator* stack_frame_deduplicator() const {
     return stack_frame_deduplicator_.get();
   }
 
-  void SetStackFrameDeduplicator(
-      std::unique_ptr<StackFrameDeduplicator> stack_frame_deduplicator);
-
   // Returns the type name deduplicator that should be used by memory dump
   // providers when doing a heap dump.
   TypeNameDeduplicator* type_name_deduplicator() const {
     return type_name_deduplicator_.get();
   }
 
-  void SetTypeNameDeduplicator(
-      std::unique_ptr<TypeNameDeduplicator> type_name_deduplicator);
+  // Returns generic string deduplicator used by other deduplicators.
+  StringDeduplicator* string_deduplicator() const {
+    return string_deduplicator_.get();
+  }
+
+  void CreateDeduplicators();
 
   void SetAllowedDumpModes(
       std::set<MemoryDumpLevelOfDetail> allowed_dump_modes);
 
   bool IsDumpModeAllowed(MemoryDumpLevelOfDetail dump_mode) const;
 
   void set_heap_profiler_breakdown_threshold_bytes(uint32_t value) {
     heap_profiler_breakdown_threshold_bytes_ = value;
   }
 
   uint32_t heap_profiler_breakdown_threshold_bytes() const {
     return heap_profiler_breakdown_threshold_bytes_;
   }
 
  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_;
 
+  // Generic string deduplicator, used by other deduplicators; must be defined
+  // after ones that depend on it.
+  std::unique_ptr<StringDeduplicator> string_deduplicator_;
+
   std::set<MemoryDumpLevelOfDetail> allowed_dump_modes_;
 
   uint32_t heap_profiler_breakdown_threshold_bytes_;
 };
 
 }  // namespace trace_event
 }  // namespace base
 
 #endif  // BASE_TRACE_EVENT_MEMORY_DUMP_SESSION_STATE_H_