[tracing] Switch to new heap dump format.

third_party/WebKit/Source/platform/PartitionAllocMemoryDumpProvider.cpp

Index: third_party/WebKit/Source/platform/PartitionAllocMemoryDumpProvider.cpp
diff --git a/third_party/WebKit/Source/platform/PartitionAllocMemoryDumpProvider.cpp b/third_party/WebKit/Source/platform/PartitionAllocMemoryDumpProvider.cpp
index 84e221517da6ffbecb161e0bd18b9928e0929e1d..1d9d502dedaccd7a771e8420dac175026a22b671 100644
--- a/third_party/WebKit/Source/platform/PartitionAllocMemoryDumpProvider.cpp
+++ b/third_party/WebKit/Source/platform/PartitionAllocMemoryDumpProvider.cpp
@@ -136,25 +136,8 @@ bool PartitionAllocMemoryDumpProvider::OnMemoryDump(
 
   MemoryDumpLevelOfDetail level_of_detail = args.level_of_detail;
   if (is_heap_profiling_enabled_) {
-    // Overhead should always be reported, regardless of light vs. heavy.
-    base::trace_event::TraceEventMemoryOverhead overhead;
-    std::unordered_map<base::trace_event::AllocationContext,
-                       base::trace_event::AllocationMetrics>
-        metrics_by_context;
-    {
-      MutexLocker locker(allocation_register_mutex_);
-      // Dump only the overhead estimation in non-detailed dumps.
-      if (level_of_detail == MemoryDumpLevelOfDetail::DETAILED) {
-        for (const auto& alloc_size : *allocation_register_) {
-          base::trace_event::AllocationMetrics& metrics =
-              metrics_by_context[alloc_size.context];
-          metrics.size += alloc_size.size;
-          metrics.count++;
-        }
-      }
-      allocation_register_->EstimateTraceMemoryOverhead(&overhead);
-    }
-    memory_dump->DumpHeapUsage(metrics_by_context, overhead, "partition_alloc");
+    MutexLocker locker(allocation_register_mutex_);
+    memory_dump->DumpHeapUsage(*allocation_register_, kPartitionAllocDumpName);
   }
 
   PartitionStatsDumperImpl partition_stats_dumper(memory_dump, level_of_detail);