[tracing] Switch to new heap dump format.

third_party/WebKit/Source/platform/heap/BlinkGCMemoryDumpProvider.cpp

 // 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 "platform/heap/BlinkGCMemoryDumpProvider.h"
 
 #include <unordered_map>
 
 #include "base/trace_event/heap_profiler_allocation_context_tracker.h"
 #include "base/trace_event/heap_profiler_allocation_register.h"
@@ skipping 49 matching lines @@
   MemoryDumpLevelOfDetail level_of_detail = args.level_of_detail;
   // In the case of a detailed dump perform a mark-only GC pass to collect
   // more detailed stats.
   if (level_of_detail == MemoryDumpLevelOfDetail::DETAILED)
     ThreadState::Current()->CollectGarbage(BlinkGC::kNoHeapPointersOnStack,
                                            BlinkGC::kTakeSnapshot,
                                            BlinkGC::kForcedGC);
   DumpMemoryTotals(memory_dump);
 
   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_);
-      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, "blink_gc");
+    MutexLocker locker(allocation_register_mutex_);
+    memory_dump->DumpHeapUsage(*allocation_register_, "blink_gc");
   }
 
   // Merge all dumps collected by ThreadHeap::collectGarbage.
   if (level_of_detail == MemoryDumpLevelOfDetail::DETAILED)
     memory_dump->TakeAllDumpsFrom(current_process_memory_dump_.get());
   return true;
 }
 
 void BlinkGCMemoryDumpProvider::OnHeapProfilingEnabled(bool enabled) {
   if (enabled) {
@@ skipping 43 matching lines @@
     allocation_register_->Insert(address, size, context);
 }
 
 void BlinkGCMemoryDumpProvider::Remove(Address address) {
   MutexLocker locker(allocation_register_mutex_);
   if (allocation_register_)
     allocation_register_->Remove(address);
 }
 
 }  // namespace blink