mac: Use -fstack-protector-strong instead of -fstack-protector-all.

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 173 matching lines @@
       "-fno-threadsafe-statics",
 
       # Not exporting C++ inline functions can generally be applied anywhere
       # so we do so here. Normal function visibility is controlled by
       # //build/config/gcc:symbol_visibility_hidden.
       "-fvisibility-inlines-hidden",
     ]
 
     # Stack protection.
     if (is_mac) {
-      cflags += [ "-fstack-protector-all" ]
+      cflags += [ "-fstack-protector-strong" ]
     } else if (is_posix && !is_chromeos && !is_nacl) {
       # TODO(phajdan.jr): Use -fstack-protector-strong when our gcc supports it.
+      # See also https://crbug.com/533294
       cflags += [ "--param=ssp-buffer-size=4" ]
 
       # The x86 toolchain currently has problems with stack-protector.
       if (is_android && current_cpu == "x86") {
         cflags += [ "-fno-stack-protector" ]
       } else {
         cflags += [ "-fstack-protector" ]
       }
     }
 
@@ skipping 1256 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
   }
 }