[tracing] Support background mode in skia memory dump provider

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 e0767526beacb4c293351dc9b401fbd7df7fabc1..c53cf7e62da82df8684a22fad8e2ef8ff142f47d 100644
--- a/skia/ext/skia_memory_dump_provider.cc
+++ b/skia/ext/skia_memory_dump_provider.cc
@@ -26,6 +26,22 @@ SkiaMemoryDumpProvider::~SkiaMemoryDumpProvider() {}
 bool SkiaMemoryDumpProvider::OnMemoryDump(
     const base::trace_event::MemoryDumpArgs& args,
     base::trace_event::ProcessMemoryDump* process_memory_dump) {
+  if (args.level_of_detail ==
+      base::trace_event::MemoryDumpLevelOfDetail::BACKGROUND) {
+    auto glyph_cache_dump =
+        process_memory_dump->CreateAllocatorDump("skia/sk_glyph_cache");
+    glyph_cache_dump->AddScalar(
+        base::trace_event::MemoryAllocatorDump::kNameSize,
+        base::trace_event::MemoryAllocatorDump::kUnitsBytes,
+        SkGraphics::GetFontCacheUsed());
+    auto resource_cache_dump =
+        process_memory_dump->CreateAllocatorDump("skia/sk_resource_cache");
+    resource_cache_dump->AddScalar(
+        base::trace_event::MemoryAllocatorDump::kNameSize,
+        base::trace_event::MemoryAllocatorDump::kUnitsBytes,
+        SkGraphics::GetResourceCacheTotalBytesUsed());
+    return true;
+  }
   SkiaTraceMemoryDumpImpl skia_dumper(args.level_of_detail,
                                       process_memory_dump);
   SkGraphics::DumpMemoryStatistics(&skia_dumper);