[tracing] Switch to new heap dump format.

base/trace_event/malloc_dump_provider.cc

Index: base/trace_event/malloc_dump_provider.cc
diff --git a/base/trace_event/malloc_dump_provider.cc b/base/trace_event/malloc_dump_provider.cc
index 3565b8b95be29c3b254f45e4b38a2af5b998768e..64a14422632571aacde12f9e0238e4420e387e5e 100644
--- a/base/trace_event/malloc_dump_provider.cc
+++ b/base/trace_event/malloc_dump_provider.cc
@@ -13,7 +13,7 @@
 #include "base/trace_event/heap_profiler_allocation_context.h"
 #include "base/trace_event/heap_profiler_allocation_context_tracker.h"
 #include "base/trace_event/heap_profiler_allocation_register.h"
-#include "base/trace_event/heap_profiler_heap_dump_writer.h"
+#include "base/trace_event/heap_profiler_event_writer.h"
 #include "base/trace_event/process_memory_dump.h"
 #include "base/trace_event/trace_event_argument.h"
 #include "build/build_config.h"
@@ -295,22 +295,10 @@ bool MallocDumpProvider::OnMemoryDump(const MemoryDumpArgs& args,
   // Enclosing all the temporariy data structures in a scope, so that the heap
   // profiler does not see unabalanced malloc/free calls from these containers.
   {
-    TraceEventMemoryOverhead overhead;
-    hash_map<AllocationContext, AllocationMetrics> metrics_by_context;
-    {
-      AutoLock lock(allocation_register_lock_);
-      if (allocation_register_) {
-        if (args.level_of_detail == MemoryDumpLevelOfDetail::DETAILED) {
-          for (const auto& alloc_size : *allocation_register_) {
-            AllocationMetrics& metrics = metrics_by_context[alloc_size.context];
-            metrics.size += alloc_size.size;
-            metrics.count++;
-          }
-        }
-        allocation_register_->EstimateTraceMemoryOverhead(&overhead);
-      }
-    }  // lock(allocation_register_lock_)
-    pmd->DumpHeapUsage(metrics_by_context, overhead, "malloc");
+    AutoLock lock(allocation_register_lock_);
+    if (allocation_register_) {
+      pmd->DumpHeapUsage(*allocation_register_, "malloc");
+    }
   }
   tid_dumping_heap_ = kInvalidThreadId;