[tracing] Add WebCache memory usage in Blink to chrome://tracing

components/web_cache/renderer/web_cache_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 "components/web_cache/renderer/web_cache_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/WebKit/public/web/WebCache.h"
+
+namespace web_cache {
+namespace {
+
+void DumpResourceStats(blink::WebCache::ResourceTypeStat resource_stat,

[Primiano Tucci (use gerrit), 2015/08/13 13:30:21]

No need to pass a copy. Add const...&

[ssid, 2015/08/13 15:25:34]

Done.

+                       const std::string resource_name,

[Primiano Tucci (use gerrit), 2015/08/13 13:30:21]

same here

[ssid, 2015/08/13 15:25:34]

Done.

+                       base::trace_event::ProcessMemoryDump* pmd) {
+  base::trace_event::MemoryAllocatorDump* allocator_dump =
+      pmd->CreateAllocatorDump(resource_name);
+  allocator_dump->AddScalar(base::trace_event::MemoryAllocatorDump::kNameSize,
+                            base::trace_event::MemoryAllocatorDump::kUnitsBytes,
+                            resource_stat.size);
+  allocator_dump->AddScalar(
+      base::trace_event::MemoryAllocatorDump::kNameObjectsCount,
+      base::trace_event::MemoryAllocatorDump::kUnitsObjects,
+      resource_stat.count);
+  allocator_dump->AddScalar("live_size",
+                            base::trace_event::MemoryAllocatorDump::kUnitsBytes,
+                            resource_stat.liveSize);
+  allocator_dump->AddScalar("decoded_size",
+                            base::trace_event::MemoryAllocatorDump::kUnitsBytes,
+                            resource_stat.decodedSize);
+  allocator_dump->AddScalar("purged_size",
+                            base::trace_event::MemoryAllocatorDump::kUnitsBytes,
+                            resource_stat.purgedSize);
+  allocator_dump->AddScalar("purgeable_size",
+                            base::trace_event::MemoryAllocatorDump::kUnitsBytes,
+                            resource_stat.purgeableSize);
+}
+
+}  // namespace
+
+// static
+WebCacheMemoryDumpProvider* WebCacheMemoryDumpProvider::GetInstance() {
+  return Singleton<WebCacheMemoryDumpProvider,
+                   LeakySingletonTraits<WebCacheMemoryDumpProvider>>::get();
+}
+
+WebCacheMemoryDumpProvider::WebCacheMemoryDumpProvider() {}
+
+WebCacheMemoryDumpProvider::~WebCacheMemoryDumpProvider() {}
+
+bool WebCacheMemoryDumpProvider::OnMemoryDump(
+    const base::trace_event::MemoryDumpArgs& args,
+    base::trace_event::ProcessMemoryDump* pmd) {
+  blink::WebCache::UsageStats memory_stats = {0};
+  blink::WebCache::getUsageStats(&memory_stats);
+
+  const std::string dump_name("web_cache");
+  base::trace_event::MemoryAllocatorDump* allocator_dump =
+      pmd->CreateAllocatorDump(dump_name);
+
+  allocator_dump->AddScalar(base::trace_event::MemoryAllocatorDump::kNameSize,
+                            base::trace_event::MemoryAllocatorDump::kUnitsBytes,
+                            memory_stats.liveSize + memory_stats.deadSize);
+  allocator_dump->AddScalar("live_size",
+                            base::trace_event::MemoryAllocatorDump::kUnitsBytes,
+                            memory_stats.liveSize);
+  allocator_dump->AddScalar("dead_size",
+                            base::trace_event::MemoryAllocatorDump::kUnitsBytes,
+                            memory_stats.deadSize);
+
+  blink::WebCache::ResourceTypeStats resource_stats;

[Primiano Tucci (use gerrit), 2015/08/13 13:30:21]

 maybe = {0} also here for consistency?

[ssid, 2015/08/13 15:25:34]

Um, it is struct of structs, so it looks dirty. The api just replaces the data
anyways, so removing the previous init to be consistent.

+  blink::WebCache::getResourceTypeStats(&resource_stats);
+  DumpResourceStats(resource_stats.images, dump_name + "/images", pmd);
+  DumpResourceStats(resource_stats.cssStyleSheets,
+                    dump_name + "/css_style_sheets", pmd);
+  DumpResourceStats(resource_stats.scripts, dump_name + "/scripts", pmd);
+  DumpResourceStats(resource_stats.xslStyleSheets,
+                    dump_name + "/xsl_style_sheets", pmd);
+  DumpResourceStats(resource_stats.fonts, dump_name + "/fonts", pmd);
+  DumpResourceStats(resource_stats.other, dump_name + "/other", pmd);
+
+  return true;
+}
+
+}  // namespace web_cache