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

skia/ext/skia_memory_dump_provider.cc

Index: skia/ext/skia_memory_dump_provider.cc
diff --git a/skia/ext/skia_memory_dump_provider.cc b/skia/ext/skia_memory_dump_provider.cc
index a7c445fd5d4f1f9b34865ac3162a3b7bf0a1688e..089711796b0f9284e202afd4e84f1c7c2fe6f8e2 100644
--- a/skia/ext/skia_memory_dump_provider.cc
+++ b/skia/ext/skia_memory_dump_provider.cc
@@ -4,6 +4,8 @@
 
 #include "skia_memory_dump_provider.h"
 
+#include "base/memory/discardable_memory_allocator.h"
+#include "base/trace_event/malloc_dump_provider.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"
@@ -26,15 +28,24 @@ bool SkiaMemoryDumpProvider::OnMemoryDump(
     base::trace_event::ProcessMemoryDump* process_memory_dump) {
   auto font_mad =
       process_memory_dump->CreateAllocatorDump("skia/sk_font_cache");
-  font_mad->AddScalar("size", "bytes", SkGraphics::GetFontCacheUsed());
-  font_mad->AddScalar("count", "objects", SkGraphics::GetFontCacheCountUsed());
+  font_mad->AddScalar(base::trace_event::MemoryAllocatorDump::kNameSize,
+                      base::trace_event::MemoryAllocatorDump::kUnitsBytes,
+                      SkGraphics::GetFontCacheUsed());
+  font_mad->AddScalar(base::trace_event::MemoryAllocatorDump::kNameObjectsCount,
+                      base::trace_event::MemoryAllocatorDump::kUnitsObjects,
+                      SkGraphics::GetFontCacheCountUsed());
 
   auto resource_mad =
       process_memory_dump->CreateAllocatorDump("skia/sk_resource_cache");
-  resource_mad->AddScalar("size", "bytes",
+  resource_mad->AddScalar(base::trace_event::MemoryAllocatorDump::kNameSize,
+                          base::trace_event::MemoryAllocatorDump::kUnitsBytes,
                           SkResourceCache::GetTotalBytesUsed());
-  // TODO(ssid): crbug.com/503168. Add sub-allocation edges from discardable or
-  // malloc memory dumps to avoid double counting.
+  const char* source_name =
+      SkResourceCache::GetDiscardableFactory()
+          ? base::DiscardableMemoryAllocator::GetMemoryPoolNameForTracing()
+          : base::trace_event::MemoryDumpManager::GetInstance()
+                ->system_allocator_pool_name();
+  process_memory_dump->AddSuballocation(resource_mad->guid(), source_name);
 
   return true;
 }