[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 12d8eb6cfcc1737ff64376c2fad81f2037aa86ad..981f3f33943f5158a571ca695de1407095503e12 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_dump_provider.h"
 #include "base/strings/stringprintf.h"
 #include "base/trace_event/memory_dump_manager.h"
 
@@ -440,6 +441,8 @@ void DiscardableSharedMemoryHeap::OnMemoryDump(
   // client.
   const int kImportance = 2;
   pmd->AddOwnershipEdge(segment_dump->guid(), shared_segment_guid, kImportance);
+  base::SharedMemoryDumpProvider::GetInstance()->AddSuballocation(
+      pmd, segment_dump->guid());
 }
 
 // static