Add more out of line copy ctors for complex classes.

tools/gn/bundle_file_rule.cc

 // Copyright 2016 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 "tools/gn/bundle_file_rule.h"
 
 #include "tools/gn/output_file.h"
 #include "tools/gn/settings.h"
 #include "tools/gn/substitution_pattern.h"
 #include "tools/gn/substitution_writer.h"
 #include "tools/gn/target.h"
 
 BundleFileRule::BundleFileRule(const std::vector<SourceFile> sources,
                                const SubstitutionPattern& pattern)
     : sources_(sources), pattern_(pattern) {}
 
+BundleFileRule::BundleFileRule(const BundleFileRule& other) = default;
+
 BundleFileRule::~BundleFileRule() {}
 
 SourceFile BundleFileRule::ApplyPatternToSource(
     const Settings* settings,
     const BundleData& bundle_data,
     const SourceFile& source_file) const {
   std::string output_path;
   for (const auto& subrange : pattern_.ranges()) {
     switch (subrange.type) {
       case SUBSTITUTION_LITERAL:
@@ skipping 21 matching lines @@
   return SourceFile(SourceFile::SWAP_IN, &output_path);
 }
 
 OutputFile BundleFileRule::ApplyPatternToSourceAsOutputFile(
     const Settings* settings,
     const BundleData& bundle_data,
     const SourceFile& source_file) const {
   return OutputFile(settings->build_settings(),
                     ApplyPatternToSource(settings, bundle_data, source_file));
 }