[memory-infra] Add API to ProcessMemoryDump to create ownership edges for base::SharedMemory

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>
 
 #include "base/base_export.h"
 
 namespace base {
 namespace trace_event {
 
 class BASE_EXPORT MemoryAllocatorDumpGuid {
  public:
+  // If the clients of base::SharedMemory should use the global dump guid(s)
+  // created by SharedMemoryTracker.
+  static bool UseSharedMemoryBasedGUIDs();
+  static void SetUseSharedMemoryBasedGUIDsForTesting();
+
   MemoryAllocatorDumpGuid();
   explicit MemoryAllocatorDumpGuid(uint64_t guid);
 
   // Utility ctor to hash a GUID if the caller prefers a string. The caller
   // still has to ensure that |guid_str| is unique, per snapshot, within the
   // global scope of all the traced processes.
   explicit MemoryAllocatorDumpGuid(const std::string& guid_str);
 
   uint64_t ToUint64() const { return guid_; }
 
@@ skipping 17 matching lines @@
  private:
   uint64_t guid_;
 
   // Deliberately copy-able.
 };
 
 }  // namespace trace_event
 }  // namespace base
 
 #endif  // BASE_TRACE_EVENT_MEMORY_ALLOCATOR_DUMP_GUID_H_