Add more out of line copy ctors for complex classes.

ui/platform_window/text_input_state.cc

 // 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.
 
 #include "ui/platform_window/text_input_state.h"
 
 namespace ui {
 
 TextInputState::TextInputState()
     : type(TEXT_INPUT_TYPE_NONE),
@@ skipping 14 matching lines @@
                                bool can_compose_inline)
     : type(type),
       flags(flags),
       text(text),
       selection_start(selection_start),
       selection_end(selection_end),
       composition_start(composition_start),
       composition_end(composition_end),
       can_compose_inline(can_compose_inline) {}
 
+TextInputState::TextInputState(const TextInputState& other) = default;
+
 bool TextInputState::operator==(const TextInputState& other) const {
   return type == other.type &&
          flags == other.flags &&
          text == other.text &&
          selection_start == other.selection_start &&
          selection_end == other.selection_end &&
          composition_start == other.composition_start &&
          composition_end == other.composition_end &&
          can_compose_inline == other.can_compose_inline;
 }
 
 }  // namespace ui