[iOS/GN] Fix compilation of ios_chrome_unittests with gn.

build/config/mac/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/sysroot.gni")
 import("//build/config/mac/mac_sdk.gni")
 
 # This is included by reference in the //build/config/compiler config that
 # is applied to all targets. It is here to separate out the logic.
 #
 # This is applied to BOTH desktop Mac and iOS targets.
 config("compiler") {
   # These flags are shared between the C compiler and linker.
   common_mac_flags = []
 
   # CPU architecture.
   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") {
-    # TODO(GYP): we may need to distinguish between "arm64", "armv7",
-    # and "armv7s" for iOS, and hence need multiple current_cpu values
-    # rather than just "arm".
+  } else if (current_cpu == "armv7" || current_cpu == "arm") {
+    common_mac_flags += [
+      "-arch",
+      "armv7",
+    ]
+  } else if (current_cpu == "arm64") {
     common_mac_flags += [
       "-arch",
       "arm64",
-      "-arch",
-      "armv7",
     ]
   }
 
   asmflags = common_mac_flags
   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" ]
 
@@ skipping 33 matching lines @@
       "-Wl,-rpath,@loader_path/../../..",
     ]
   }
 }
 
 # On Mac, this is used only for executables.
 config("mac_executable_flags") {
   # Remove this when targeting >=10.7 since it is the default in that config.
   ldflags = [ "-Wl,-pie" ]  # Position independent.
 }