[sql] Enable disabled clang warnings.

third_party/sqlite/sqlite.gyp

 # Copyright (c) 2012 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.
 
 {
   'variables': {
     'use_system_sqlite%': 0,
     'required_sqlite_version': '3.6.1',
   },
   'target_defaults': {
@@ skipping 115 matching lines @@
           ],
           'direct_dependent_settings': {
             'include_dirs': [
               '.',
               '../..',
             ],
           },
           'msvs_disabled_warnings': [
             4018, 4244, 4267,
           ],
-          'variables': {
-            'clang_warning_flags': [
-              # sqlite does `if (*a++ && *b++);` in a non-buggy way.
-              '-Wno-empty-body',
-              # sqlite has some `unsigned < 0` checks.
-              '-Wno-tautological-compare',
-              # Needed because we don't have this commit yet:
-              # https://github.com/mackyle/sqlite/commit/25df0fa050dcc9be7fb937b8e25be24049b3fef0
-              '-Wno-pointer-bool-conversion',
-            ],
-          },
           'conditions': [
             ['OS=="linux"', {
               'link_settings': {
                 'libraries': [
                   '-ldl',
                 ],
               },
             }],
             ['OS == "mac" or OS == "ios"', {
               'link_settings': {
@@ skipping 87 matching lines @@
             '../icu/icu.gyp:icuuc',
           ],
           'sources': [
             'src/ext/icu/icu.c',
           ],
         },
       ],
     }],
   ],
 }