[tracing] Introduce MemoryDumpArgs to enable light and heavy dumps

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..6d981363fb4ef7a32268bb20b41319dc757a6bb0 100644
--- a/skia/ext/skia_memory_dump_provider.cc
+++ b/skia/ext/skia_memory_dump_provider.cc
@@ -23,7 +23,11 @@ SkiaMemoryDumpProvider::SkiaMemoryDumpProvider() {}
 SkiaMemoryDumpProvider::~SkiaMemoryDumpProvider() {}
 
 bool SkiaMemoryDumpProvider::OnMemoryDump(
+    const base::trace_event::MemoryDumpArgs& args,
     base::trace_event::ProcessMemoryDump* process_memory_dump) {
+  // TODO(ssid): Use MemoryDumpArgs to create light dumps when requested
+  // (crbug.com/499731).
+
   auto font_mad =
       process_memory_dump->CreateAllocatorDump("skia/sk_font_cache");
   font_mad->AddScalar("size", "bytes", SkGraphics::GetFontCacheUsed());