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

gpu/command_buffer/client/cmd_buffer_helper.cc

Index: gpu/command_buffer/client/cmd_buffer_helper.cc
diff --git a/gpu/command_buffer/client/cmd_buffer_helper.cc b/gpu/command_buffer/client/cmd_buffer_helper.cc
index 42cb4165a8484722521ce04bfa8bd615eefe3ea4..192105111dd24cb14d2071beab19815995923bc2 100644
--- a/gpu/command_buffer/client/cmd_buffer_helper.cc
+++ b/gpu/command_buffer/client/cmd_buffer_helper.cc
@@ -10,6 +10,7 @@
 
 #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"
@@ -375,10 +376,6 @@ bool CommandBufferHelper::OnMemoryDump(
   if (!HaveRingBuffer())
     return true;
 
-  const uint64_t tracing_process_id =
-      base::trace_event::MemoryDumpManager::GetInstance()
-          ->GetTracingProcessId();
-
   MemoryAllocatorDump* dump = pmd->CreateAllocatorDump(base::StringPrintf(
       "gpu/command_buffer_memory/buffer_%d", ring_buffer_id_));
   dump->AddScalar(MemoryAllocatorDump::kNameSize,
@@ -388,10 +385,19 @@ bool CommandBufferHelper::OnMemoryDump(
     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) {
+      base::SharedMemoryTracker::AddOwnershipEdges(pmd, dump->guid(),
+                                                   *shared_memory);
+    } else {
+      const uint64_t tracing_process_id =
+          base::trace_event::MemoryDumpManager::GetInstance()
+              ->GetTracingProcessId();
+      auto guid = GetBufferGUIDForTracing(tracing_process_id, ring_buffer_id_);
+      const int kImportance = 2;
+      pmd->CreateSharedGlobalAllocatorDump(guid);
+      pmd->AddOwnershipEdge(dump->guid(), guid, kImportance);
+    }
   }
 
   return true;