Add defaulted move constructors for some types that just got copy constructors

webrtc/modules/desktop_capture/desktop_region.h

 /*
  *  Copyright (c) 2013 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
@@ skipping 30 matching lines @@
     int32_t left;
     int32_t right;
   };
 
   typedef std::vector<RowSpan> RowSpanSet;
 
   // Row represents a single row of a region. A row is set of rectangles that
   // have the same vertical position.
   struct Row {
     Row(const Row&);
+    Row(Row&&);
     Row(int32_t top, int32_t bottom);
     ~Row();
 
     int32_t top;
     int32_t bottom;
 
     RowSpanSet spans;
   };
 
   // Type used to store list of rows in the region. The bottom position of row
@@ skipping 98 matching lines @@
   // merged row.
   void MergeWithPrecedingRow(Rows::iterator row);
 
   Rows rows_;
 };
 
 }  // namespace webrtc
 
 #endif  // WEBRTC_MODULES_DESKTOP_CAPTURE_DESKTOP_REGION_H_