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

components/web_cache/renderer/web_cache_memory_dump_provider.cc

Index: components/web_cache/renderer/web_cache_memory_dump_provider.cc
diff --git a/components/web_cache/renderer/web_cache_memory_dump_provider.cc b/components/web_cache/renderer/web_cache_memory_dump_provider.cc
new file mode 100644
index 0000000000000000000000000000000000000000..228a8cfbf83ced808c4f82f3027b73a746fa9131
--- /dev/null
+++ b/components/web_cache/renderer/web_cache_memory_dump_provider.cc
@@ -0,0 +1,96 @@
+// 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/format_macros.h"
+#include "base/strings/stringprintf.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,
+                       const std::string resource_name,
+                       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);
+}
+
+}  // 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);
+
+  uint64 tracing_process_id =
+      base::trace_event::MemoryDumpManager::GetInstance()
+          ->GetTracingProcessId();
+  std::string dump_name =
+      base::StringPrintf("web_cache/renderer_%" PRIx64, tracing_process_id);
+  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;
+  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);
+
+  auto shared_guid = base::trace_event::MemoryAllocatorDumpGuid(
+      base::StringPrintf("web-cache-x-process/%" PRIx64, tracing_process_id));
+  pmd->CreateSharedGlobalAllocatorDump(shared_guid);
+
+  // By creating an edge with a higher |importance| (w.r.t. browser-side dumps)
+  // the tracing UI will account the effective size of the allocation to the
+  // child.
+  const int kImportance = 2;
+  pmd->AddOwnershipEdge(allocator_dump->guid(), shared_guid, kImportance);
+  return true;
+}
+
+}  // namespace web_cache