Update build configuration to support iOS targets

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 107 matching lines @@
     if (is_mac) {
       cflags += [ "-fstack-protector-all" ]
     } else if (is_linux) {
       cflags += [
         "-fstack-protector",
         "--param=ssp-buffer-size=4",
       ]
     }
 
     # Linker warnings.
-    if (!(is_chromeos && current_cpu == "arm") && !is_mac) {
+    if (!(is_chromeos && current_cpu == "arm") && !is_mac && !is_ios) {
       # TODO(jochen): Enable this on chromeos on arm. http://crbug.com/356580
       ldflags += [ "-Wl,--fatal-warnings" ]
     }
 
     # Common options for AddressSanitizer, LeakSanitizer, ThreadSanitizer and
     # MemorySanitizer
     if (using_sanitizer) {
       cflags += [
         "-fno-omit-frame-pointer",
         "-gline-tables-only",
@@ skipping 40 matching lines @@
     if (current_cpu == "x64") {
       common_mac_flags += [
         "-arch",
         "x86_64",
       ]
     } else if (current_cpu == "x86") {
       common_mac_flags += [
         "-arch",
         "i386",
       ]
+    } else if (current_cpu == "arm") {
+      common_mac_flags += [
+        "-arch",
+        "armv7",
+      ]
     }
 
     cflags += common_mac_flags
 
     # Without this, the constructors and destructors of a C++ object inside
     # an Objective C struct won't be called, which is very bad.
     cflags_objcc = [ "-fobjc-call-cxx-cdtors" ]
 
     cflags_c += [ "-std=c99" ]
 
@@ skipping 287 matching lines @@
         ldflags += [ "-target arm-linux-androideabi" ]
       } else if (current_cpu == "x86") {
         cflags += [ "-target x86-linux-androideabi" ]
         ldflags += [ "-target x86-linux-androideabi" ]
       }
     }
   }
 }
 
 config("compiler_arm_fpu") {
-  if (current_cpu == "arm") {
+  if (current_cpu == "arm" && !is_ios) {
     cflags = [ "-mfpu=$arm_fpu" ]
   }
 }
 
 # runtime_library -------------------------------------------------------------
 #
 # Sets the runtime library and associated options.
 #
 # How do you determine what should go in here vs. "compiler" above? Consider if
 # a target might choose to use a different runtime library (ignore for a moment
@@ skipping 593 matching lines @@
       cflags += [ "-gsplit-dwarf" ]
     }
   }
 }
 
 config("no_symbols") {
   if (!is_win) {
     cflags = [ "-g0" ]
   }
 }