Fix the release build.

apps/benchmark/event.cc

 // Copyright 2015 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 "apps/benchmark/event.h"
 
 #include <map>
 #include <stack>
 
 #include "base/json/json_reader.h"
@@ skipping 37 matching lines @@
                         const std::string& key,
                         std::string* output) {
   const base::Value* value;
   if (!event_dict->Get(key, &value)) {
     LOG(ERROR) << "Incorrect trace event (missing " + key + "): "
                << *event_dict;
     return false;
   }
 
   if (value->IsType(base::Value::TYPE_INTEGER)) {
-    int id_int;
+    int id_int = 0;
     // We already verified the type, so it should be an integer.
     DCHECK(value->GetAsInteger(&id_int));
     *output = base::IntToString(id_int);
   } else if (value->IsType(base::Value::TYPE_STRING)) {
     DCHECK(value->GetAsString(output));
   } else {
     LOG(ERROR) << "Incorrect trace event (" + key +
                       " not a string or integer): "
                << *event_dict;
     return false;
@@ skipping 195 matching lines @@
   }
 
   if (!JoinEvents(event_list))
     return false;
 
   if (!ParseEvents(event_list, result))
     return false;
   return true;
 }
 }  // namespace benchmark