Update from https://crrev.com/327068

base/trace_event/memory_allocator_attributes_type_info.cc

Index: base/trace_event/memory_allocator_attributes_type_info.cc
diff --git a/base/trace_event/memory_allocator_attributes_type_info.cc b/base/trace_event/memory_allocator_attributes_type_info.cc
new file mode 100644
index 0000000000000000000000000000000000000000..7d1e61cada7f3423a2d48e7b188fbf13b8195f2c
--- /dev/null
+++ b/base/trace_event/memory_allocator_attributes_type_info.cc
@@ -0,0 +1,61 @@
+// 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 "base/trace_event/memory_allocator_attributes_type_info.h"
+
+#include "base/lazy_instance.h"
+#include "base/logging.h"
+
+namespace base {
+namespace trace_event {
+
+namespace {
+base::LazyInstance<const std::string> kNotFound = LAZY_INSTANCE_INITIALIZER;
+
+std::string GetKey(const std::string& allocator_name,
+                   const std::string& attribute_name) {
+  return allocator_name + "/" + attribute_name;
+}
+}  // namespace
+
+MemoryAllocatorAttributesTypeInfo::MemoryAllocatorAttributesTypeInfo() {
+}
+
+MemoryAllocatorAttributesTypeInfo::~MemoryAllocatorAttributesTypeInfo() {
+}
+
+const std::string& MemoryAllocatorAttributesTypeInfo::Get(
+    const std::string& allocator_name,
+    const std::string& attribute_name) const {
+  auto it = type_info_map_.find(GetKey(allocator_name, attribute_name));
+  if (it == type_info_map_.end())
+    return kNotFound.Get();
+  return it->second;
+}
+
+void MemoryAllocatorAttributesTypeInfo::Set(const std::string& allocator_name,
+                                            const std::string& attribute_name,
+                                            const std::string& attribute_type) {
+  std::string key = GetKey(allocator_name, attribute_name);
+  DCHECK_EQ(0u, type_info_map_.count(key));
+  type_info_map_[key] = attribute_type;
+}
+
+bool MemoryAllocatorAttributesTypeInfo::Exists(
+    const std::string& allocator_name,
+    const std::string& attribute_name) const {
+  return type_info_map_.count(GetKey(allocator_name, attribute_name)) == 1;
+}
+
+void MemoryAllocatorAttributesTypeInfo::Update(
+    const MemoryAllocatorAttributesTypeInfo& other) {
+  for (auto it = other.type_info_map_.begin();
+       it != other.type_info_map_.end(); ++it) {
+    bool no_duplicates = type_info_map_.insert(*it).second;
+    DCHECK(no_duplicates) << "Duplicated allocator attribute " << it->first;
+  }
+}
+
+}  // namespace trace_event
+}  // namespace base