[tracing] Simplify design of MemoryAllocatorDump

base/trace_event/malloc_dump_provider.cc

 // 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.
 
 #include "base/trace_event/malloc_dump_provider.h"
 
 #include <malloc.h>
 
 #include "base/trace_event/process_memory_dump.h"
 
 namespace base {
 namespace trace_event {
 
 namespace {
 
 const char kDumperFriendlyName[] = "Malloc";
-const char kDumperName[] = "malloc";
 
 }  // namespace
 
 // static
 MallocDumpProvider* MallocDumpProvider::GetInstance() {
   return Singleton<MallocDumpProvider,
                    LeakySingletonTraits<MallocDumpProvider>>::get();
 }
 
 MallocDumpProvider::MallocDumpProvider() {
 }
 
 MallocDumpProvider::~MallocDumpProvider() {
 }
 
 // Called at trace dump point time. Creates a snapshot the memory counters for
 // the current process.
 bool MallocDumpProvider::DumpInto(ProcessMemoryDump* pmd) {
   struct mallinfo info = mallinfo();
   DCHECK(info.uordblks > 0);
   DCHECK_GE(info.arena + info.hblkhd, info.uordblks);
 
-  MemoryAllocatorDump* dump = pmd->CreateAllocatorDump(kDumperName);
+  MemoryAllocatorDump* dump =
+      pmd->CreateAllocatorDump("malloc", MemoryAllocatorDump::kRootHeap);
   if (!dump)
     return false;
 
   // When the system allocator is implemented by tcmalloc, the total physical
   // size is given by |arena| and |hblkhd| is 0. In case of Android's jemalloc
   // |arena| is 0 and the outer pages size is reported by |hblkhd|. In case of
   // dlmalloc the total is given by |arena| + |hblkhd|.
   // For more details see link: http://goo.gl/fMR8lF.
   dump->set_physical_size_in_bytes(info.arena + info.hblkhd);
 
   // mallinfo doesn't support any allocated object count.
   dump->set_allocated_objects_count(0);
 
   // Total allocated space is given by |uordblks|.
   dump->set_allocated_objects_size_in_bytes(info.uordblks);
 
   return true;
 }
 
 const char* MallocDumpProvider::GetFriendlyName() const {
   return kDumperFriendlyName;
 }
 
 }  // namespace trace_event
 }  // namespace base