Update //base to chromium 9659b08ea5a34f889dc4166217f438095ddc10d2

base/trace_event/trace_event_memory_overhead.h

Index: base/trace_event/trace_event_memory_overhead.h
diff --git a/base/trace_event/trace_event_memory_overhead.h b/base/trace_event/trace_event_memory_overhead.h
new file mode 100644
index 0000000000000000000000000000000000000000..8ecf12dc969eb4f0dc26516061450cff5d229509
--- /dev/null
+++ b/base/trace_event/trace_event_memory_overhead.h
@@ -0,0 +1,71 @@
+// 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.
+
+#ifndef BASE_TRACE_EVENT_TRACE_EVENT_MEMORY_OVERHEAD_H_
+#define BASE_TRACE_EVENT_TRACE_EVENT_MEMORY_OVERHEAD_H_
+
+#include "base/base_export.h"
+#include "base/containers/hash_tables.h"
+#include "base/containers/small_map.h"
+
+namespace base {
+
+class RefCountedString;
+class Value;
+
+namespace trace_event {
+
+class ProcessMemoryDump;
+
+// Used to estimate the memory overhead of the tracing infrastructure.
+class BASE_EXPORT TraceEventMemoryOverhead {
+ public:
+  TraceEventMemoryOverhead();
+  ~TraceEventMemoryOverhead();
+
+  // Use this method to account the overhead of an object for which an estimate
+  // is known for both the allocated and resident memory.
+  void Add(const char* object_type,
+           size_t allocated_size_in_bytes,
+           size_t resident_size_in_bytes);
+
+  // Similar to Add() above, but assumes that
+  // |resident_size_in_bytes| == |allocated_size_in_bytes|.
+  void Add(const char* object_type, size_t allocated_size_in_bytes);
+
+  // Specialized profiling functions for commonly used object types.
+  void AddString(const std::string& str);
+  void AddValue(const Value& value);
+  void AddRefCountedString(const RefCountedString& str);
+
+  // Call this after all the Add* methods above to account the memory used by
+  // this TraceEventMemoryOverhead instance itself.
+  void AddSelf();
+
+  // Adds up and merges all the values from |other| to this instance.
+  void Update(const TraceEventMemoryOverhead& other);
+
+  void DumpInto(const char* base_name, ProcessMemoryDump* pmd) const;
+
+ private:
+  struct ObjectCountAndSize {
+    size_t count;
+    size_t allocated_size_in_bytes;
+    size_t resident_size_in_bytes;
+  };
+  using map_type = SmallMap<hash_map<const char*, ObjectCountAndSize>, 16>;
+  map_type allocated_objects_;
+
+  void AddOrCreateInternal(const char* object_type,
+                           size_t count,
+                           size_t allocated_size_in_bytes,
+                           size_t resident_size_in_bytes);
+
+  DISALLOW_COPY_AND_ASSIGN(TraceEventMemoryOverhead);
+};
+
+}  // namespace trace_event
+}  // namespace base
+
+#endif  // BASE_TRACE_EVENT_TRACE_EVENT_MEMORY_OVERHEAD_H_