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

components/metrics/leak_detector/leak_detector.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 "components/metrics/leak_detector/leak_detector.h"
 
 #include <stdint.h>
 
 #include "base/allocator/allocator_extension.h"
 #include "base/bind.h"
@@ skipping 137 matching lines @@
   // The effective max value of |alloc_size| is thus half its nominal max value.
   uintptr_t ptr_value =
       (hook_data.entered_hook ? 1 : 0) | (hook_data.alloc_size << 1);
   g_hook_data_tls.Get().Set(reinterpret_cast<void*>(ptr_value));
 }
 
 }  // namespace
 
 LeakDetector::LeakReport::LeakReport() {}
 
+LeakDetector::LeakReport::LeakReport(const LeakReport& other) = default;
+
 LeakDetector::LeakReport::~LeakReport() {}
 
 // static
 LeakDetector* LeakDetector::GetInstance() {
   return g_instance.Pointer();
 }
 
 void LeakDetector::Init(float sampling_rate,
                         size_t max_call_stack_unwind_depth,
                         uint64_t analysis_interval_bytes,
@@ skipping 161 matching lines @@
     return;
   }
 
   for (const LeakReport& report : reports) {
     base::AutoLock lock(observers_lock_);
     FOR_EACH_OBSERVER(Observer, observers_, OnLeakFound(report));
   }
 }
 
 }  // namespace metrics