Enable Wextra and Wno-unused-parameters in default cflags

services/prediction/dictionary_service.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 <algorithm>
 #include <deque>
 #include <fstream>
 #include <string>
 
 #include "base/base_paths.h"
@@ skipping 26 matching lines @@
 void DictionaryService::CreatDictFromEmbeddedDataIfNotExist(
     const std::string path) {
   if (std::ifstream(path.c_str()))
     return;
   std::ofstream dic_file(path.c_str(),
                          std::ofstream::out | std::ofstream::binary);
   dic_file.write(prediction::kDictFile.data, prediction::kDictFile.size);
   dic_file.close();
 }
 
-latinime::Dictionary* const DictionaryService::OpenDictionary(
+latinime::Dictionary* DictionaryService::OpenDictionary(
     const std::string path,
     const int start_offset,
     const int size,
     const bool is_updatable) {
   latinime::DictionaryStructureWithBufferPolicy::StructurePolicyPtr
       dictionary_structure_with_buffer_policy(
           latinime::DictionaryStructureWithBufferPolicyFactory::
               newPolicyForExistingDictFile(path.c_str(), start_offset, size,
                                            is_updatable));
   if (!dictionary_structure_with_buffer_policy) {
@@ skipping 133 matching lines @@
     prev_word_codepoint_count[i] = prev_word_size;
     are_beginning_of_sentence[i] = prev_words[i]->is_beginning_of_sentence;
   }
   latinime::PrevWordsInfo prev_words_info =
       latinime::PrevWordsInfo(prev_word_codepoints, prev_word_codepoint_count,
                               are_beginning_of_sentence, prevwords_count);
   return prev_words_info;
 }
 
 }  // namespace prediction