[tracing] Switch to new heap dump format.

base/trace_event/memory_dump_session_state.h

Index: base/trace_event/memory_dump_session_state.h
diff --git a/base/trace_event/memory_dump_session_state.h b/base/trace_event/memory_dump_session_state.h
index 46092cb4832d7d8d69f51cfadd143760c26b0b15..92c3ecb8e485497da69d926dd7fb07c89aaa5789 100644
--- a/base/trace_event/memory_dump_session_state.h
+++ b/base/trace_event/memory_dump_session_state.h
@@ -29,17 +29,18 @@ class BASE_EXPORT MemoryDumpSessionState
     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);
@@ -66,6 +67,10 @@ class BASE_EXPORT MemoryDumpSessionState
   // 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_;