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

components/drive/file_system_interface.h

 // Copyright (c) 2012 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_DRIVE_FILE_SYSTEM_INTERFACE_H_
 #define COMPONENTS_DRIVE_FILE_SYSTEM_INTERFACE_H_
 
 #include <stdint.h>
 
 #include <string>
@@ skipping 26 matching lines @@
   std::string hash;
   base::FilePath path;
 };
 
 // Struct to represent a search result for SearchMetadata().
 struct MetadataSearchResult {
   MetadataSearchResult(const base::FilePath& path,
                        bool is_directory,
                        const std::string& highlighted_base_name,
                        const std::string& md5);
+  MetadataSearchResult(const MetadataSearchResult& other);
 
   // The two members are used to create FileEntry object.
   base::FilePath path;
   bool is_directory;
 
   // The base name to be displayed in the UI. The parts matched the search
   // query are highlighted with <b> tag. Meta characters are escaped like &lt;
   //
   // Why HTML? we could instead provide matched ranges using pairs of
   // integers, but this is fragile as we'll eventually converting strings
@@ skipping 410 matching lines @@
 
   // Calculates evictable cache size.
   // |callback| must not be null.
   virtual void CalculateEvictableCacheSize(
       const EvictableCacheSizeCallback& callback) = 0;
 };
 
 }  // namespace drive
 
 #endif  // COMPONENTS_DRIVE_FILE_SYSTEM_INTERFACE_H_