Disable "taking address of packed member" clang warning.

build/config/compiler/BUILD.gn

 # Copyright (c) 2013 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.
 
 import("//build/config/android/config.gni")
 import("//build/config/chrome_build.gni")
 import("//build/config/compiler/compiler.gni")
 import("//build/config/nacl/config.gni")
 import("//build/toolchain/cc_wrapper.gni")
 import("//build/toolchain/toolchain.gni")
@@ skipping 976 matching lines @@
       # http://crbug.com/255186
       "-Wno-deprecated-register",
 
       # TODO(thakis): This used to be implied by -Wno-unused-function,
       # which we no longer use. Check if it makes sense to remove
       # this as well. http://crbug.com/316352
       "-Wno-unneeded-internal-declaration",
 
       # TODO(hans): Get this cleaned up, http://crbug.com/428099
       "-Wno-inconsistent-missing-override",
+
+      # TODO(eugenis): Clean up, http://crbug.com/619640
+      "-Wno-address-of-packed-member",
     ]
 
     # NaCl's Clang compiler and Chrome's hermetic Clang compiler will almost
     # always have different versions. Certain flags may not be recognized by
     # one version or the other.
     if (!is_nacl) {
       # Flags NaCl (Clang 3.7) does not recognize.
       cflags += [
         # TODO(thakis): Enable this, crbug.com/507717
         "-Wno-shift-negative-value",
@@ skipping 476 matching lines @@
 
 if (is_ios || is_mac) {
   # On Mac and iOS, this enables support for ARC (automatic ref-counting).
   # See http://clang.llvm.org/docs/AutomaticReferenceCounting.html.
   config("enable_arc") {
     common_flags = [ "-fobjc-arc" ]
     cflags_objc = common_flags
     cflags_objcc = common_flags
   }
 }