tracing: Make ConvertableToTraceFormat move-only scoped_ptr

base/trace_event/heap_profiler_stack_frame_deduplicator.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_HEAP_PROFILER_STACK_FRAME_DEDUPLICATOR_H_
 #define BASE_TRACE_EVENT_HEAP_PROFILER_STACK_FRAME_DEDUPLICATOR_H_
 
 #include <map>
 #include <string>
 #include <vector>
@@ skipping 29 matching lines @@
     // parent frame (when it is at the bottom of the call stack).
     int parent_frame_index;
 
     // Indices into |frames_| of frames called from the current frame.
     std::map<StackFrame, int> children;
   };
 
   using ConstIterator = std::vector<FrameNode>::const_iterator;
 
   StackFrameDeduplicator();
+  ~StackFrameDeduplicator() override;
 
   // Inserts a backtrace where |beginFrame| is a pointer to the bottom frame
   // (e.g. main) and |endFrame| is a pointer past the top frame (most recently
   // called function), and returns the index of its leaf node in |frames_|.
   // Returns -1 if the backtrace is empty.
   int Insert(const StackFrame* beginFrame, const StackFrame* endFrame);
 
   // Iterators over the frame nodes in the call tree.
   ConstIterator begin() const { return frames_.begin(); }
   ConstIterator end() const { return frames_.end(); }
 
   // Writes the |stackFrames| dictionary as defined in https://goo.gl/GerkV8 to
   // the trace log.
   void AppendAsTraceFormat(std::string* out) const override;
 
   // Estimates memory overhead including |sizeof(StackFrameDeduplicator)|.
   void EstimateTraceMemoryOverhead(TraceEventMemoryOverhead* overhead) override;
 
  private:
-  ~StackFrameDeduplicator() override;
-
   std::map<StackFrame, int> roots_;
   std::vector<FrameNode> frames_;
 
   DISALLOW_COPY_AND_ASSIGN(StackFrameDeduplicator);
 };
 
 }  // namespace trace_event
 }  // namespace base
 
 #endif  // BASE_TRACE_EVENT_HEAP_PROFILER_STACK_FRAME_DEDUPLICATOR_H_