Set using_sanitizer if use_cfi_diag is true.

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/chromecast_build.gni")
 import("//build/config/compiler/compiler.gni")
 import("//build/toolchain/cc_wrapper.gni")
 import("//build/toolchain/toolchain.gni")
@@ skipping 314 matching lines @@
 
     # Use pipes for communicating between sub-processes. Faster.
     cflags += [ "-pipe" ]
 
     ldflags += [
       "-Wl,-z,noexecstack",
       "-Wl,-z,now",
       "-Wl,-z,relro",
     ]
     if (!using_sanitizer) {
-      if (!use_cfi_diag) {
-        ldflags += [ "-Wl,-z,defs" ]
-      }
+      ldflags += [ "-Wl,-z,defs" ]
 
       # Functions interposed by the sanitizers can make ld think
       # that some libraries aren't needed when they actually are,
       # http://crbug.com/234010. As workaround, disable --as-needed.
       if (!is_nacl && !is_android) {
         # TODO(pcc): Fix linker bug which requires us to link pthread
         # unconditionally here (crbug.com/623236).
         ldflags += [
           "-Wl,--no-as-needed",
           "-lpthread",
@@ skipping 1464 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
   }
 }