components: Add out-of-line copy ctors for complex classes.

components/translate/core/common/language_detection_details.h

 // Copyright 2014 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 COMPONENTS_TRANSLATE_CORE_COMMON_LANGUAGE_DETECTION_DETAILS_H_
 #define COMPONENTS_TRANSLATE_CORE_COMMON_LANGUAGE_DETECTION_DETAILS_H_
 
 #include <string>
 
 #include "base/strings/string16.h"
 #include "base/time/time.h"
 #include "url/gurl.h"
 
 namespace translate {
 
 struct LanguageDetectionDetails {
   LanguageDetectionDetails();
+  LanguageDetectionDetails(const LanguageDetectionDetails& other);
   ~LanguageDetectionDetails();
 
   // The time when this was created.
   base::Time time;
 
   // The URL.
   GURL url;
 
   // The language detected by the content (Content-Language).
   std::string content_language;
@@ skipping 15 matching lines @@
   // The adopted language.
   std::string adopted_language;
 
   // The contents which is used for detection.
   base::string16 contents;
 };
 
 }  // namespace translate
 
 #endif  // COMPONENTS_TRANSLATE_CORE_COMMON_LANGUAGE_DETECTION_DETAILS_H_