win clang: don't disable -Wself-assign

third_party/libpng/BUILD.gn

 # Copyright 2014 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.
 
 config("libpng_config") {
   include_dirs = [ "." ]
 
   defines = [
     "CHROME_PNG_WRITE_SUPPORT",
     "PNG_USER_CONFIG",
@@ skipping 43 matching lines @@
 
   if (is_win && is_component_build) {
     defines = [ "PNG_BUILD_DLL" ]
   }
 
   public_configs = [ ":libpng_config" ]
 
   public_deps = [
     "//third_party/zlib",
   ]
+
+  if (is_win && is_clang) {
+    cflags = [ "-Wno-self-assign" ]  # http://crbug.com/505306.

[Nico, 2015/06/29 23:51:02]

Is the plan to fix these? If not and this is supposed to stay here, instead add
a comment what it's needed for. (And it should probably be only `if (is_clang)`
– right now we happen to build third-party code with -Wall with clang-cl but not
with regular clang, but since everything's close to building in that mode we
might as well enable -Wall for third-party code soon too)

[scottmg, 2015/06/30 00:32:55]

Done.

+  }
 }
 
 if (is_win) {
   component("libpng") {
     public_deps = [
       ":libpng_sources",
     ]
   }
 } else {
   group("libpng") {
     public_deps = [
       ":libpng_sources",
     ]
   }
 }