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

content/common/discardable_shared_memory_heap.h

Index: content/common/discardable_shared_memory_heap.h
diff --git a/content/common/discardable_shared_memory_heap.h b/content/common/discardable_shared_memory_heap.h
index 7ded677c3cc75630b61181c16a4b20258943550e..e8f48546cdda8f1da2f9687b19c2efeed1cb71fc 100644
--- a/content/common/discardable_shared_memory_heap.h
+++ b/content/common/discardable_shared_memory_heap.h
@@ -88,6 +88,11 @@ class CONTENT_EXPORT DiscardableSharedMemoryHeap {
   // Dumps memory statistics for chrome://tracing.
   bool OnMemoryDump(base::trace_event::ProcessMemoryDump* pmd);
 
+  // Creates a common dump for all the sub-allocated objects from discardable
+  // memory.
+  static void CreateAllocatedObjectsDump(
+      base::trace_event::ProcessMemoryDump* pmd);
+
   // Returns a unique identifier for a given tuple of (process id, segment id)
   // that can be used to match memory dumps across different processes.
   static base::trace_event::MemoryAllocatorDumpGuid GetSegmentGUIDForTracing(