Remove unnecessary clang flags for ICU

icu.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.
 
 {
   'includes': [
     'icu.gypi',
   ],
   'variables': {
     'use_system_icu%': 0,
@@ skipping 179 matching lines @@
               'source/i18n',
             ],
           },
           'variables': {
             'clang_warning_flags': [
               # ICU uses its own deprecated functions.
               '-Wno-deprecated-declarations',
               # ICU prefers `a && b || c` over `(a && b) || c`.
               '-Wno-logical-op-parentheses',
               # ICU has some `unsigned < 0` checks.
               '-Wno-tautological-compare',

[Nico, 2015/05/28 02:33:52]

Since the .gn file doesn't have it, you might be able to remove
-Wno-logical-op-parentheses and -Wno-tautological-compare from this target as
well?

[jungshik at Google, 2015/05/28 18:10:19]

BUILD.gn has both of them under |config("icu_code")| section, which I guess is
applied to both icuuc and icui18n targets. 

-              # Looks like a real issue, see http://crbug.com/114660
-              '-Wno-return-type-c-linkage',
             ],
           },
           # Since ICU wants to internally use its own deprecated APIs, don't
           # complain about it.
           'cflags': [
             '-Wno-deprecated-declarations',
           ],
           'cflags_cc': [
             '-frtti',
           ],
@@ skipping 372 matching lines @@
           },
           'includes': [
             '../../build/shim_headers.gypi',
           ],
           'toolsets': ['target'],
         },
       ], # targets
     }],
   ], # conditions
 }