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

components/invalidation/public/single_object_invalidation_set.cc

 // 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.
 
 #include "components/invalidation/public/single_object_invalidation_set.h"
 
 #include "base/values.h"
 #include "components/invalidation/public/invalidation_util.h"
 
 namespace syncer {
 
 SingleObjectInvalidationSet::SingleObjectInvalidationSet() {}
 
+SingleObjectInvalidationSet::SingleObjectInvalidationSet(
+    const SingleObjectInvalidationSet& other) = default;
+
 SingleObjectInvalidationSet::~SingleObjectInvalidationSet() {}
 
 void SingleObjectInvalidationSet::Insert(const Invalidation& invalidation) {
   invalidations_.insert(invalidation);
 }
 
 void SingleObjectInvalidationSet::InsertAll(
     const SingleObjectInvalidationSet& other) {
   invalidations_.insert(other.begin(), other.end());
 }
@@ skipping 82 matching lines @@
     if (!invalidation) {
       DLOG(WARNING) << "Failed to parse invalidation at index " << i;
       return false;
     }
     invalidations_.insert(*invalidation);
   }
   return true;
 }
 
 }  // namespace syncer