Use correct linker flags for iOS release builds.

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")
 if (current_cpu == "arm") {
   import("//build/config/arm.gni")
 }
 if (current_cpu == "mipsel" || current_cpu == "mips64el") {
@@ skipping 1164 matching lines @@
     # TODO(jdduke) Re-enable on mips after resolving linking
     # issues with libc++ (crbug.com/456380).
     if (current_cpu != "mipsel" && current_cpu != "mips64el") {
       common_optimize_on_ldflags += [
         # Warn in case of text relocations.
         "-Wl,--warn-shared-textrel",
       ]
     }
   }
 
-  if (is_mac) {
+  if (is_mac || is_ios) {
     if (symbol_level == 2) {
       # Mac dead code stripping requires symbols.
       common_optimize_on_ldflags += [ "-Wl,-dead_strip" ]
     }
   } else {
     # Non-Mac Posix linker flags.
     common_optimize_on_ldflags += [
       # Specifically tell the linker to perform optimizations.
       # See http://lwn.net/Articles/192624/ .
       "-Wl,-O1",
@@ skipping 120 matching lines @@
       cflags += [ "-gsplit-dwarf" ]
     }
   }
 }
 
 config("no_symbols") {
   if (!is_win) {
     cflags = [ "-g0" ]
   }
 }