[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..3ade476e2934d04380a2d8d68bc304eebc8ab100 100644
--- a/skia/ext/skia_memory_dump_provider.cc
+++ b/skia/ext/skia_memory_dump_provider.cc
@@ -26,16 +26,28 @@ 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());
-
-  auto resource_mad =
-      process_memory_dump->CreateAllocatorDump("skia/sk_resource_cache");
-  resource_mad->AddScalar("size", "bytes",
-                          SkResourceCache::GetTotalBytesUsed());
-  // TODO(ssid): crbug.com/503168. Add sub-allocation edges from discardable or
-  // malloc memory dumps to avoid double counting.
-
+  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());
+
+  size_t skia_resource_cache_size = SkResourceCache::GetTotalBytesUsed();
+  if (skia_resource_cache_size > 0) {

[petrcermak, 2015/07/29 11:53:34]

Shouldn't we report zero explicitly as well?

[ssid, 2015/07/29 16:20:51]

Yea i think it makes more sense to dump 0

+    auto resource_mad =
+        process_memory_dump->CreateAllocatorDump("skia/sk_resource_cache");
+    resource_mad->AddScalar(base::trace_event::MemoryAllocatorDump::kNameSize,
+                            base::trace_event::MemoryAllocatorDump::kUnitsBytes,
+                            skia_resource_cache_size);
+    if (SkResourceCache::GetDiscardableFactory()) {
+      process_memory_dump->AddSuballocation(resource_mad->guid(),

[petrcermak, 2015/07/29 11:53:34]

You could use a ternary operator or factor out the name to reduce code
duplication.

+                                            "discardable/allocated_objects");
+    } else {
+      process_memory_dump->AddSuballocation(resource_mad->guid(),
+                                            "malloc/allocated_objects");

[petrcermak, 2015/07/29 11:53:34]

Please use the base::trace_event::MallocDumpProvider::kAllocatedObjects constant
instead.

[ssid, 2015/07/29 16:20:51]

Done.

+    }
+  }
   return true;
 }