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

gpu/command_buffer/client/cmd_buffer_helper.cc

 // Copyright (c) 2012 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.
 
 // This file contains the implementation of the command buffer helper class.
 
 #include "gpu/command_buffer/client/cmd_buffer_helper.h"
 
 #include <stdint.h>
 
 #include <algorithm>
 #include "base/logging.h"
+#include "base/memory/shared_memory_tracker.h"
 #include "base/strings/stringprintf.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "base/time/time.h"
 #include "base/trace_event/memory_allocator_dump.h"
 #include "base/trace_event/memory_dump_manager.h"
 #include "base/trace_event/process_memory_dump.h"
 #include "base/trace_event/trace_event.h"
 #include "gpu/command_buffer/common/buffer.h"
 #include "gpu/command_buffer/common/command_buffer.h"
 #include "gpu/command_buffer/common/constants.h"
@@ skipping 347 matching lines @@
 
   MemoryAllocatorDump* dump = pmd->CreateAllocatorDump(base::StringPrintf(
       "gpu/command_buffer_memory/buffer_%d", ring_buffer_id_));
   dump->AddScalar(MemoryAllocatorDump::kNameSize,
                   MemoryAllocatorDump::kUnitsBytes, ring_buffer_size_);
 
   if (args.level_of_detail != MemoryDumpLevelOfDetail::BACKGROUND) {
     dump->AddScalar(
         "free_size", MemoryAllocatorDump::kUnitsBytes,
         GetTotalFreeEntriesNoWaiting() * sizeof(CommandBufferEntry));
-    auto guid = GetBufferGUIDForTracing(tracing_process_id, ring_buffer_id_);
-    const int kImportance = 2;
-    pmd->CreateSharedGlobalAllocatorDump(guid);
-    pmd->AddOwnershipEdge(dump->guid(), guid, kImportance);
+    auto shared_memory = ring_buffer_->backing()->shared_memory();
+    if (shared_memory) {
+      auto guid = GetBufferGUIDForTracing(tracing_process_id, ring_buffer_id_);
+      const int kImportance = 2;
+      pmd->CreateSharedGlobalAllocatorDump(guid);
+      pmd->AddOwnershipEdge(dump->guid(), guid, kImportance);
+      base::SharedMemoryTracker::AddOwnershipEdgeToSharedGlobalDump(pmd, guid,
+          shared_memory->handle(), shared_memory->mapped_size());
+    }
   }
 
   return true;
 }
 
 }  // namespace gpu