Update from https://crrev.com/333737

base/trace_event/malloc_dump_provider.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_MALLOC_DUMP_PROVIDER_H_
 #define BASE_TRACE_EVENT_MALLOC_DUMP_PROVIDER_H_
 
 #include <istream>
 
 #include "base/memory/singleton.h"
 #include "base/trace_event/memory_dump_provider.h"
 
 namespace base {
 namespace trace_event {
 
 // Dump provider which collects process-wide memory stats.
 class BASE_EXPORT MallocDumpProvider : public MemoryDumpProvider {
  public:
+  // Name of the allocated_objects dump. Use this to declare suballocator dumps
+  // from other dump providers.
+  static const char kAllocatedObjects[];
+
   static MallocDumpProvider* GetInstance();
 
   // MemoryDumpProvider implementation.
   bool OnMemoryDump(ProcessMemoryDump* pmd) override;
 
  private:
   friend struct DefaultSingletonTraits<MallocDumpProvider>;
 
   MallocDumpProvider();
   ~MallocDumpProvider() override;
 
   DISALLOW_COPY_AND_ASSIGN(MallocDumpProvider);
 };
 
 }  // namespace trace_event
 }  // namespace base
 
 #endif  // BASE_TRACE_EVENT_MALLOC_DUMP_PROVIDER_H_