win clang: don't disable -Wself-assign

third_party/libpng/libpng.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.
 
 {
   'targets': [
     {
       'target_name': 'libpng',
       'dependencies': [
         '../zlib/zlib.gyp:zlib',
       ],
+      'variables': {
+        # Upstream uses self-assignment to avoid warnings.
+        'clang_warning_flags': [ '-Wno-self-assign' ]
+      },
       'defines': [
         'CHROME_PNG_WRITE_SUPPORT',
         'PNG_USER_CONFIG',
       ],
       'sources': [
         'png.c',
         'png.h',
         'pngconf.h',
         'pngerror.c',
         'pnggccrd.c',
@@ skipping 38 matching lines @@
         }],
         ['OS=="win" and component=="shared_library"', {
           'defines': [
             'PNG_BUILD_DLL',
             'PNG_NO_MODULEDEF',
           ],
           'direct_dependent_settings': {
             'defines': [
               'PNG_USE_DLL',
             ],
-          },          
+          },
         }],
         ['OS=="android"', {
           'toolsets': ['target', 'host'],
           'defines': [
             'CHROME_PNG_READ_PACK_SUPPORT',  # Required by freetype.
           ],
           'direct_dependent_settings': {
             'defines': [
               'CHROME_PNG_READ_PACK_SUPPORT',
             ],
           },
         }],
       ],
     },
   ]
 }