Update from https://crrev.com/316786

base/trace_event/process_memory_dump.h

Index: base/trace_event/process_memory_dump.h
diff --git a/base/trace_event/process_memory_dump.h b/base/trace_event/process_memory_dump.h
new file mode 100644
index 0000000000000000000000000000000000000000..ae42987dfd12cd86f9cfcf28343bb7391d2d6cf7
--- /dev/null
+++ b/base/trace_event/process_memory_dump.h
@@ -0,0 +1,37 @@
+// 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_PROCESS_MEMORY_DUMP_H_
+#define BASE_TRACE_EVENT_PROCESS_MEMORY_DUMP_H_
+
+#include "base/base_export.h"
+#include "base/basictypes.h"
+#include "base/trace_event/trace_event_impl.h"
+
+namespace base {
+namespace trace_event {
+
+// A container which holds the dumps produced by the MemoryDumpProvider(s)
+// for a specific process. ProcessMemoryDump is as a strongly typed container
+// which enforces the data model for each memory dump point.
+// At trace generation time (i.e. when AppendAsTraceFormat is called) the
+// ProcessMemoryDump will compose a key-value dictionary of the various dumps
+// obtained during at trace dump point time.
+class BASE_EXPORT ProcessMemoryDump : public ConvertableToTraceFormat {
+ public:
+  ProcessMemoryDump();
+
+  // ConvertableToTraceFormat implementation.
+  void AppendAsTraceFormat(std::string* out) const override;
+
+ private:
+  ~ProcessMemoryDump() override;
+
+  DISALLOW_COPY_AND_ASSIGN(ProcessMemoryDump);
+};
+
+}  // namespace trace_event
+}  // namespace base
+
+#endif  // BASE_TRACE_EVENT_PROCESS_MEMORY_DUMP_H_