[tracing] Switch to new heap dump format.

base/trace_event/heap_profiler_type_name_deduplicator.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_HEAP_PROFILER_TYPE_NAME_DEDUPLICATOR_H_
 #define BASE_TRACE_EVENT_HEAP_PROFILER_TYPE_NAME_DEDUPLICATOR_H_
 
 #include <map>
 #include <string>
+#include <vector>
 
 #include "base/base_export.h"
 #include "base/macros.h"
-#include "base/trace_event/trace_event_impl.h"
 
 namespace base {
 namespace trace_event {
 
+class StringDeduplicator;
 class TraceEventMemoryOverhead;
+class TracedValue;
 
-// Data structure that assigns a unique numeric ID to |const char*|s.
-class BASE_EXPORT TypeNameDeduplicator : public ConvertableToTraceFormat {
+// Data structure that assigns a unique numeric ID to type names.
+class BASE_EXPORT TypeNameDeduplicator {
  public:
-  TypeNameDeduplicator();
-  ~TypeNameDeduplicator() override;
+  // |string_deduplication| is used during serialization, and is expected
+  // to outlive instances of this class.
+  explicit TypeNameDeduplicator(StringDeduplicator* string_deduplicator);
+  ~TypeNameDeduplicator();
 
   // Inserts a type name and returns its ID.
   int Insert(const char* type_name);
 
-  // Writes the type ID -> type name mapping to the trace log.
-  void AppendAsTraceFormat(std::string* out) const override;
+  // Appends {ID -> type name} mappings that were added after the last call
+  // to this function. |traced_value| must be in 'array' mode.
+  void SerializeIncrementally(TracedValue* traced_value);
 
   // Estimates memory overhead including |sizeof(TypeNameDeduplicator)|.
-  void EstimateTraceMemoryOverhead(TraceEventMemoryOverhead* overhead) override;
+  void EstimateTraceMemoryOverhead(TraceEventMemoryOverhead* overhead);
 
  private:
-  // Map from type name to type ID.
-  std::map<const char*, int> type_ids_;
+  StringDeduplicator* string_deduplicator_;
+
+  // Map from type name to type ID. The reason this class has its own map
+  // and does not use string_deduplicator_ in Insert() is that type names
+  // are sometimes file names, and we need post-process them to extract
+  // categories.
+  using TypeMap = std::map<const char*, int>;
+  TypeMap type_ids_;
+  std::vector<const TypeMap::value_type*> new_type_ids_;
 
   DISALLOW_COPY_AND_ASSIGN(TypeNameDeduplicator);
 };
 
 }  // namespace trace_event
 }  // namespace base
 
 #endif  // BASE_TRACE_EVENT_HEAP_PROFILER_TYPE_NAME_DEDUPLICATOR_H_