[WIP] Add SharedMemoryTracker to dump base::SharedMemory usage

components/discardable_memory/common/discardable_shared_memory_heap.cc

Index: components/discardable_memory/common/discardable_shared_memory_heap.cc
diff --git a/components/discardable_memory/common/discardable_shared_memory_heap.cc b/components/discardable_memory/common/discardable_shared_memory_heap.cc
index 7eacbeeec77e03d56bbe2efe6edd459c30cdc4d1..55b334a094567aadec517f67b27279539ac109aa 100644
--- a/components/discardable_memory/common/discardable_shared_memory_heap.cc
+++ b/components/discardable_memory/common/discardable_shared_memory_heap.cc
@@ -11,6 +11,7 @@
 #include "base/macros.h"
 #include "base/memory/discardable_shared_memory.h"
 #include "base/memory/ptr_util.h"
+#include "base/memory/shared_memory_tracker.h"
 #include "base/strings/stringprintf.h"
 #include "base/trace_event/memory_dump_manager.h"
 
@@ -422,36 +423,9 @@ void DiscardableSharedMemoryHeap::OnMemoryDump(
   // dumper active and the single ownership edge will become a no-op in the UI.
   // The global dump is created as a weak dump so that the segment is removed if
   // the browser does not dump it (segment was purged).
-  const uint64_t tracing_process_id =
-      base::trace_event::MemoryDumpManager::GetInstance()
-          ->GetTracingProcessId();
-  base::trace_event::MemoryAllocatorDumpGuid shared_segment_guid =
-      GetSegmentGUIDForTracing(tracing_process_id, segment_id);
-  // TODO(ssid): Make this weak once the GUID created is consistent
-  // crbug.com/661257.
-  pmd->CreateSharedGlobalAllocatorDump(shared_segment_guid);
-
-  // The size is added to the global dump so that it gets propagated to both the
-  // dumps associated.
-  pmd->GetSharedGlobalAllocatorDump(shared_segment_guid)
-      ->AddScalar(base::trace_event::MemoryAllocatorDump::kNameSize,
-                  base::trace_event::MemoryAllocatorDump::kUnitsBytes,
-                  allocated_objects_size_in_bytes);
-
-  // By creating an edge with a higher |importance| (w.r.t. browser-side dumps)
-  // the tracing UI will account the effective size of the segment to the
-  // client.
-  const int kImportance = 2;
-  pmd->AddOwnershipEdge(segment_dump->guid(), shared_segment_guid, kImportance);
-}
-
-// static
-base::trace_event::MemoryAllocatorDumpGuid
-DiscardableSharedMemoryHeap::GetSegmentGUIDForTracing(
-    uint64_t tracing_process_id,
-    int32_t segment_id) {
-  return base::trace_event::MemoryAllocatorDumpGuid(base::StringPrintf(
-      "discardable-x-process/%" PRIx64 "/%d", tracing_process_id, segment_id));
+  base::SharedMemoryTracker::AddOwnershipEdges(pmd, segment_dump->guid(),
+                                               shared_memory->handle(),
+                                               allocated_objects_size_in_bytes);
 }
 
 base::trace_event::MemoryAllocatorDump*