[tracing] Switch to new heap dump format.

base/trace_event/sharded_allocation_register.cc

 // Copyright 2017 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/sharded_allocation_register.h"
 
 #include "base/trace_event/trace_event_memory_overhead.h"
 #include "build/build_config.h"
 
 namespace base {
@@ skipping 51 matching lines @@
     RegisterAndLock& ral = allocation_registers_[i];
     AutoLock lock(ral.lock);
     allocated += ral.allocation_register.EstimateAllocatedMemory();
     resident += ral.allocation_register.EstimateResidentMemory();
   }
 
   overhead->Add(TraceEventMemoryOverhead::kHeapProfilerAllocationRegister,
                 allocated, resident);
 }
 
-ShardedAllocationRegister::OutputMetrics
-ShardedAllocationRegister::UpdateAndReturnsMetrics(MetricsMap& map) const {
-  OutputMetrics output_metrics;
-  output_metrics.size = 0;
-  output_metrics.count = 0;
+void ShardedAllocationRegister::VisitAllocations(
+    const AllocationVisitor& visitor) const {
   for (size_t i = 0; i < ShardCount; ++i) {
     RegisterAndLock& ral = allocation_registers_[i];
     AutoLock lock(ral.lock);
-    for (const auto& alloc_size : ral.allocation_register) {
-      AllocationMetrics& metrics = map[alloc_size.context];
-      metrics.size += alloc_size.size;
-      metrics.count++;
-
-      output_metrics.size += alloc_size.size;
-      output_metrics.count++;
+    for (const auto& alloc : ral.allocation_register) {
+      visitor.Run(alloc);
     }
   }
-  return output_metrics;
 }
 
 ShardedAllocationRegister::RegisterAndLock::RegisterAndLock() = default;
 ShardedAllocationRegister::RegisterAndLock::~RegisterAndLock() = default;
 
 }  // namespace trace_event
 }  // namespace base