[memory-infra] Add method to override importance of ownership edges

base/trace_event/memory_allocator_dump_guid.h

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef BASE_TRACE_EVENT_MEMORY_ALLOCATOR_DUMP_GUID_H_
 #define BASE_TRACE_EVENT_MEMORY_ALLOCATOR_DUMP_GUID_H_
 
 #include <stdint.h>
 
 #include <string>
@@ skipping 21 matching lines @@
   bool empty() const { return guid_ == 0u; }
 
   bool operator==(const MemoryAllocatorDumpGuid& other) const {
     return guid_ == other.guid_;
   }
 
   bool operator!=(const MemoryAllocatorDumpGuid& other) const {
     return !(*this == other);
   }
 
+  bool operator<(const MemoryAllocatorDumpGuid& other) const {
+    return guid_ < other.guid_;
+  }
+
  private:
   uint64_t guid_;
 
   // Deliberately copy-able.
 };
 
 }  // namespace trace_event
 }  // namespace base
 
 #endif  // BASE_TRACE_EVENT_MEMORY_ALLOCATOR_DUMP_GUID_H_