Compile rtc_base_objc and rtc_api_objc for Mac

webrtc/base/BUILD.gn

Index: webrtc/base/BUILD.gn
diff --git a/webrtc/base/BUILD.gn b/webrtc/base/BUILD.gn
index fa8ddff7513a8acc4dbc128385b75d8cda60c5ea..3957ebe76b7afac73012fb660749cd32f55fa253 100644
--- a/webrtc/base/BUILD.gn
+++ b/webrtc/base/BUILD.gn
@@ -617,7 +617,7 @@ static_library("rtc_base") {
   }
 }
 
-if (is_ios) {
+if (is_ios || is_mac) {

[tkchin_webrtc, 2016/02/03 08:26:49]

Might need the deployment target check here too.

[hjon_webrtc, 2016/02/04 01:43:03]

I added the deployment target check and added the same variables to
build_overrides/webrtc.gni. However, when I tested this (with `gn gen out
--args='target_os="mac" target_cpu="x86"'`), I received the error listed below.
Is there a way to get around this?

ERROR at //webrtc/BUILD.gn:13:1: Value collision.
import("build/webrtc.gni")
^------------------------
This import contains "mac_deployment_target"
See //build_overrides/webrtc.gni:27:25: defined here.
mac_deployment_target = "10.10"
                        ^------
Which would clobber the one in your current scope
See //build/config/mac/mac_sdk.gni:12:27: defined here.
  mac_deployment_target = "10.6"
                          ^-----
Executing import should not conflict with anything in the current
scope unless the values are identical.

[kjellander_webrtc, 2016/02/08 09:25:52]

Argh, I realize build_overrides/webrtc.gni can only be used to specify a
standalone-WebRTC value for variables that only exists in own GN build (i.e. not
defined in any of the Chromium parts). That is only true for the
mac_deployment_target_{major,minor} variables, not mac_deployment_target.

Dirk: Do you know what we should do here? Maybe you know a better way to do what
hjon wants here, that could avoid adding the mac_deployment_target_{major,minor}
variables as well?

   source_set("rtc_base_objc") {
     deps = [
       ":rtc_base",