[tracing] Add SkResourceCache as suballocation to avoid double counting.

content/child/child_discardable_shared_memory_manager.cc

 // Copyright 2014 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.
 
 #include "content/child/child_discardable_shared_memory_manager.h"
 
 #include "base/atomic_sequence_num.h"
 #include "base/bind.h"
 #include "base/debug/crash_logging.h"
 #include "base/memory/discardable_memory.h"
@@ skipping 174 matching lines @@
     heap_.MergeIntoFreeLists(leftover.Pass());
   }
 
   MemoryUsageChanged(heap_.GetSize(), heap_.GetSizeOfFreeLists());
 
   return make_scoped_ptr(new DiscardableMemoryImpl(this, new_span.Pass()));
 }
 
 bool ChildDiscardableSharedMemoryManager::OnMemoryDump(
     base::trace_event::ProcessMemoryDump* pmd) {
+  base::trace_event::MemoryAllocatorDump* objects_dump =
+      pmd->CreateAllocatorDump(GetMemoryPoolNameForTracing());
+  base::trace_event::MemoryAllocatorDump* discardable_segments_dump =
+      pmd->CreateAllocatorDump("discardable/segments");
+  pmd->AddOwnershipEdge(objects_dump->guid(),
+                        discardable_segments_dump->guid());
+
   base::AutoLock lock(lock_);
   return heap_.OnMemoryDump(pmd);
 }
 
 void ChildDiscardableSharedMemoryManager::ReleaseFreeMemory() {
   base::AutoLock lock(lock_);
 
   size_t heap_size_prior_to_releasing_memory = heap_.GetSize();
 
   // Release both purged and free memory.
@@ skipping 85 matching lines @@
       "discardable-memory-allocated";
   base::debug::SetCrashKeyValue(kDiscardableMemoryAllocatedKey,
                                 base::Uint64ToString(new_bytes_total));
 
   static const char kDiscardableMemoryFreeKey[] = "discardable-memory-free";
   base::debug::SetCrashKeyValue(kDiscardableMemoryFreeKey,
                                 base::Uint64ToString(new_bytes_free));
 }
 
 }  // namespace content