patch from chinmaygarde@ to make progress on mac, ios.

build/config/ios/ios_sdk.gni

Index: build/config/ios/ios_sdk.gni
diff --git a/build/config/ios/ios_sdk.gni b/build/config/ios/ios_sdk.gni
index cb2708b76c107d329bf17c5611fbbcd76aa713b3..ebbb7c9c57e1587440a7b1d912bd380a38487a10 100644
--- a/build/config/ios/ios_sdk.gni
+++ b/build/config/ios/ios_sdk.gni
@@ -1,4 +1,4 @@
-# Copyright 2014 The Chromium Authors. All rights reserved.
+# Copyright 2015 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.
 
@@ -7,14 +7,16 @@ declare_args() {
   # value of use_ios_simulator.
   ios_sdk_path = ""
 
-  # Set to true when targeting a simulator build on iOS. False means that the
-  # target is for running on the device. The default value is to use the
-  # Simulator except when targeting GYP's Xcode builds (for compat with the
-  # existing GYP build).
-  use_ios_simulator = true
+  use_ios_simulator = target_cpu == "x86" || target_cpu == "x64"
 
   # Version of iOS that we're targeting.
-  ios_deployment_target = "6.0"
+  ios_deployment_target = "7.0"
+
+  # The iOS Code signing identity to use
+  # TODO(GYP), TODO(sdfresne): Consider having a separate
+  # ios_enable_code_signing_flag=<bool> flag to make the invocation clearer.
+  ios_enable_code_signing = true
+  ios_code_signing_identity = ""
 }
 
 if (ios_sdk_path == "") {
@@ -28,3 +30,24 @@ if (ios_sdk_path == "") {
       exec_script("ios_sdk.py", [ _ios_sdk_to_query ], "list lines")
   ios_sdk_path = _ios_sdk_result[0]
 }
+
+if (use_ios_simulator) {
+  # Always disable code signing on the simulator
+  ios_enable_code_signing = false
+  ios_code_signing_identity = ""
+}
+
+if (ios_enable_code_signing) {
+  # If an identity is not provided, look for one on the host
+  if (ios_code_signing_identity == "") {
+    _ios_identities = exec_script("find_signing_identity.py", [], "list lines")
+    ios_code_signing_identity = _ios_identities[0]
+  }
+
+  if (ios_code_signing_identity == "") {
+    print("Tried to prepare a device build without specifying a code signing")
+    print("identity and could not detect one automatically either.")
+    print("TIP: Simulator builds dont require code signing...")
+    assert(false)
+  }
+}