[tracing] Add a dump provider to dump process memory totals.

base/trace_event/process_memory_dump.h

 // 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 {
 
+class ProcessMemoryTotals;
+
 // 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;
 
+  void SetProcessTotals(scoped_ptr<ProcessMemoryTotals> pmt);
+
+  const ProcessMemoryTotals* process_totals() const {
+    return process_totals_.get();
+  }
+
  private:
+  scoped_ptr<ProcessMemoryTotals> process_totals_;
+
   ~ProcessMemoryDump() override;
 
   DISALLOW_COPY_AND_ASSIGN(ProcessMemoryDump);
 };
 
 }  // namespace trace_event
 }  // namespace base
 
 #endif  // BASE_TRACE_EVENT_PROCESS_MEMORY_DUMP_H_