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

base/memory/shared_memory_handle.h

Index: base/memory/shared_memory_handle.h
diff --git a/base/memory/shared_memory_handle.h b/base/memory/shared_memory_handle.h
index 7be0614fb27c5d79cb3bdb7458a402a8315f16c2..70ea814bd08e3d16e444d6f2180d6dc151b8b4f3 100644
--- a/base/memory/shared_memory_handle.h
+++ b/base/memory/shared_memory_handle.h
@@ -7,6 +7,7 @@
 
 #include <stddef.h>
 
+#include "base/trace_event/memory_allocator_dump_guid.h"
 #include "base/unguessable_token.h"
 #include "build/build_config.h"
 
@@ -162,6 +163,10 @@ class BASE_EXPORT SharedMemoryHandle {
   int Release();
 #endif
 
+  std::string GetGUIDNameForTracing() const;
+
+  trace_event::MemoryAllocatorDumpGuid GetGUIDForTracing() const;
+
  private:
 #if defined(OS_MACOSX) && !defined(OS_IOS)
   friend class SharedMemory;