[tracing] Adding Skia memory dump provider with cache totals

skia/ext/skia_memory_dump_provider.cc

+// Copyright 2015 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "skia_memory_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"
+#include "third_party/skia/include/core/SkGraphics.h"
+#include "third_party/skia/src/core/SkResourceCache.h"
+
+namespace skia {
+
+// static
+SkiaMemoryDumpProvider* SkiaMemoryDumpProvider::GetInstance() {
+  return Singleton<SkiaMemoryDumpProvider,
+                   LeakySingletonTraits<SkiaMemoryDumpProvider>>::get();
+}
+
+SkiaMemoryDumpProvider::SkiaMemoryDumpProvider() {}
+
+SkiaMemoryDumpProvider::~SkiaMemoryDumpProvider() {}
+
+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.
+
+  return true;
+}
+
+}  // namespace skia