[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 b189b629ce84c39e3d4cd72da30c077858b77c32..0642d3d4cac353b01fd6ae60632c77bc09c2585f 100644
--- a/third_party/WebKit/Source/platform/PartitionAllocMemoryDumpProvider.cpp
+++ b/third_party/WebKit/Source/platform/PartitionAllocMemoryDumpProvider.cpp
@@ -131,25 +131,8 @@ bool PartitionAllocMemoryDumpProvider::OnMemoryDump(
 
   MemoryDumpLevelOfDetail levelOfDetail = args.level_of_detail;
   if (m_isHeapProfilingEnabled) {
-    // Overhead should always be reported, regardless of light vs. heavy.
-    base::trace_event::TraceEventMemoryOverhead overhead;
-    base::hash_map<base::trace_event::AllocationContext,
-                   base::trace_event::AllocationMetrics>
-        metricsByContext;
-    {
-      MutexLocker locker(m_allocationRegisterMutex);
-      // Dump only the overhead estimation in non-detailed dumps.
-      if (levelOfDetail == MemoryDumpLevelOfDetail::DETAILED) {
-        for (const auto& allocSize : *m_allocationRegister) {
-          base::trace_event::AllocationMetrics& metrics =
-              metricsByContext[allocSize.context];
-          metrics.size += allocSize.size;
-          metrics.count++;
-        }
-      }
-      m_allocationRegister->EstimateTraceMemoryOverhead(&overhead);
-    }
-    memoryDump->DumpHeapUsage(metricsByContext, overhead, "partition_alloc");
+    MutexLocker locker(m_allocationRegisterMutex);
+    memoryDump->DumpHeapUsage(*m_allocationRegister, kPartitionAllocDumpName);
   }
 
   PartitionStatsDumperImpl partitionStatsDumper(memoryDump, levelOfDetail);