[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 047f2c336d5c6295086316b12f883811ab9f2b0c..e6fb555a3211c5531d66ba65c09aba46e09bd121 100644
--- a/base/trace_event/malloc_dump_provider.cc
+++ b/base/trace_event/malloc_dump_provider.cc
@@ -15,7 +15,7 @@
 #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"
@@ -297,35 +297,25 @@ bool MallocDumpProvider::OnMemoryDump(const MemoryDumpArgs& args,
   // Enclosing all the temporary data structures in a scope, so that the heap
   // profiler does not see unbalanced malloc/free calls from these containers.
   {
-    size_t shim_allocated_objects_size = 0;
-    size_t shim_allocated_objects_count = 0;
-    TraceEventMemoryOverhead overhead;
-    std::unordered_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++;
-
-            // Aggregate data for objects allocated through the shim.
-            shim_allocated_objects_size += alloc_size.size;
-            shim_allocated_objects_count++;
-          }
+    AutoLock lock(allocation_register_lock_);
+    if (allocation_register_) {
+      if (args.level_of_detail == MemoryDumpLevelOfDetail::DETAILED) {
+        size_t shim_allocated_objects_size = 0;
+        size_t shim_allocated_objects_count = 0;
+        for (const auto& alloc_size : *allocation_register_) {
+          // Aggregate data for objects allocated through the shim.
+          shim_allocated_objects_size += alloc_size.size;
+          shim_allocated_objects_count++;
         }
-        allocation_register_->EstimateTraceMemoryOverhead(&overhead);
+        inner_dump->AddScalar("shim_allocated_objects_size",
+                              MemoryAllocatorDump::kUnitsBytes,
+                              shim_allocated_objects_size);
+        inner_dump->AddScalar("shim_allocator_object_count",
+                              MemoryAllocatorDump::kUnitsObjects,
+                              shim_allocated_objects_count);
       }
-
-      inner_dump->AddScalar("shim_allocated_objects_size",
-                             MemoryAllocatorDump::kUnitsBytes,
-                             shim_allocated_objects_size);
-      inner_dump->AddScalar("shim_allocator_object_count",
-                             MemoryAllocatorDump::kUnitsObjects,
-                             shim_allocated_objects_count);
-    }  // lock(allocation_register_lock_)
-    pmd->DumpHeapUsage(metrics_by_context, overhead, "malloc");
+      pmd->DumpHeapUsage(*allocation_register_, "malloc");
+    }
   }
   tid_dumping_heap_ = kInvalidThreadId;