Don't use deprecated ListValue::Append(Value*) overload.

net/log/trace_net_log_observer_unittest.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 "net/log/trace_net_log_observer.h"
 
 #include <memory>
 #include <string>
 #include <vector>
 
@@ skipping 109 matching lines @@
         continue;
       }
       std::string category;
       if (!dict->GetString("cat", &category)) {
         ADD_FAILURE()
             << "Unexpected item without a category field in trace_events";
         continue;
       }
       if (category != kNetLogTracingCategory)
         continue;
-      filtered_trace_events->Append(dict->DeepCopy());
+      filtered_trace_events->Append(dict->CreateDeepCopy());
     }
     return filtered_trace_events;
   }
 
   base::ListValue* trace_events() const { return trace_events_.get(); }
 
   TestNetLog* net_log() { return &net_log_; }
 
   TraceNetLogObserver* trace_net_log_observer() const {
     return trace_net_log_observer_.get();
@@ skipping 225 matching lines @@
   EXPECT_TRUE(item1->GetString("args.params.foo", &item1_params));
   EXPECT_EQ("bar", item1_params);
 
   EXPECT_TRUE(item2->GetString("args.params", &item2_params));
   EXPECT_TRUE(item2_params.empty());
 }
 
 }  // namespace
 
 }  // namespace net