[Tracing] Introduce HeapDumpWriter helper class

base/trace_event/process_memory_dump.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_PROCESS_MEMORY_DUMP_H_
 #define BASE_TRACE_EVENT_PROCESS_MEMORY_DUMP_H_
 
 #include <vector>
 
 #include "base/base_export.h"
@@ skipping 12 matching lines @@
 #if defined(OS_POSIX) && !defined(OS_NACL)
 #define COUNT_RESIDENT_BYTES_SUPPORTED
 #endif
 
 namespace base {
 namespace trace_event {
 
 class ConvertableToTraceFormat;
 class MemoryDumpManager;
 class MemoryDumpSessionState;
+class TracedValue;
 
 // ProcessMemoryDump is as a strongly typed container which holds the dumps
 // produced by the MemoryDumpProvider(s) for a specific process.
 class BASE_EXPORT ProcessMemoryDump {
  public:
   struct MemoryAllocatorDumpEdge {
     MemoryAllocatorDumpGuid source;
     MemoryAllocatorDumpGuid target;
     int importance;
     const char* type;
   };
 
   // Maps allocator dumps absolute names (allocator_name/heap/subheap) to
   // MemoryAllocatorDump instances.
   using AllocatorDumpsMap =
       SmallMap<hash_map<std::string, MemoryAllocatorDump*>>;
 
+  using HeapDumpsMap =
+      SmallMap<hash_map<std::string, scoped_refptr<TracedValue>>>;
+
 #if defined(COUNT_RESIDENT_BYTES_SUPPORTED)
   // Returns the total bytes resident for a virtual address range, with given
   // |start_address| and |mapped_size|. |mapped_size| is specified in bytes. The
   // value returned is valid only if the given range is currently mmapped by the
   // process. The |start_address| must be page-aligned.
   static size_t CountResidentBytes(void* start_address, size_t mapped_size);
 #endif
 
   ProcessMemoryDump(const scoped_refptr<MemoryDumpSessionState>& session_state);
   ~ProcessMemoryDump();
@@ skipping 28 matching lines @@
   MemoryAllocatorDump* CreateSharedGlobalAllocatorDump(
       const MemoryAllocatorDumpGuid& guid);
 
   // Looks up a shared MemoryAllocatorDump given its guid.
   MemoryAllocatorDump* GetSharedGlobalAllocatorDump(
       const MemoryAllocatorDumpGuid& guid) const;
 
   // Returns the map of the MemoryAllocatorDumps added to this dump.
   const AllocatorDumpsMap& allocator_dumps() const { return allocator_dumps_; }
 
+  // Adds a heap dump for the allocator with |absolute_name|. The |TracedValue|
+  // must have the correct format. |trace_event::HeapDumper| will generate such
+  // a value from a |trace_event::AllocationRegister|.
+  void AddHeapDump(const std::string& absolute_name,
+                   scoped_refptr<TracedValue> heap_dump);
+
   // Adds an ownership relationship between two MemoryAllocatorDump(s) with the
   // semantics: |source| owns |target|, and has the effect of attributing
   // the memory usage of |target| to |source|. |importance| is optional and
   // relevant only for the cases of co-ownership, where it acts as a z-index:
   // the owner with the highest importance will be attributed |target|'s memory.
   void AddOwnershipEdge(const MemoryAllocatorDumpGuid& source,
                         const MemoryAllocatorDumpGuid& target,
                         int importance);
   void AddOwnershipEdge(const MemoryAllocatorDumpGuid& source,
                         const MemoryAllocatorDumpGuid& target);
@@ skipping 40 matching lines @@
  private:
   void AddAllocatorDumpInternal(MemoryAllocatorDump* mad);
 
   ProcessMemoryTotals process_totals_;
   bool has_process_totals_;
 
   ProcessMemoryMaps process_mmaps_;
   bool has_process_mmaps_;
 
   AllocatorDumpsMap allocator_dumps_;
+  HeapDumpsMap heap_dumps_;
 
   // ProcessMemoryDump handles the memory ownership of all its belongings.
   ScopedVector<MemoryAllocatorDump> allocator_dumps_storage_;
 
   // State shared among all PMDs instances created in a given trace session.
   scoped_refptr<MemoryDumpSessionState> session_state_;
 
   // Keeps track of relationships between MemoryAllocatorDump(s).
   std::vector<MemoryAllocatorDumpEdge> allocator_dumps_edges_;
 
   DISALLOW_COPY_AND_ASSIGN(ProcessMemoryDump);
 };
 
 }  // namespace trace_event
 }  // namespace base
 
 #endif  // BASE_TRACE_EVENT_PROCESS_MEMORY_DUMP_H_