Add config for ios-device-xcode-clang bot

ios/build/bots/chromium.mac/ios-device-xcode-clang.json

Index: ios/build/bots/chromium.mac/ios-device-xcode-clang.json
diff --git a/ios/build/bots/chromium.mac/ios-device.json b/ios/build/bots/chromium.mac/ios-device-xcode-clang.json
similarity index 88%
copy from ios/build/bots/chromium.mac/ios-device.json
copy to ios/build/bots/chromium.mac/ios-device-xcode-clang.json
index 27e0dbba0aa5a25fa73625fb4c6557f1063f00d0..a08037a7dc6635e1fab1b161d46c0eeecfb14896 100644
--- a/ios/build/bots/chromium.mac/ios-device.json
+++ b/ios/build/bots/chromium.mac/ios-device-xcode-clang.json
@@ -1,6 +1,6 @@
 {
   "owners": [
-    "dpranke",
+    "sdefresne",

[Dirk Pranke, 2016/11/16 01:09:40]

awww ...

[smut, 2016/11/16 01:12:44]

Maybe it should be you and him and not me. I don't know anything about the
differences between Chromium clang and Xcode clang. But this section in the
config has proven largely pointless.

     "smut"
   ],
   "comments": [
@@ -24,11 +24,11 @@
     "is_component_build=false",
     "use_goma=true",
     "goma_dir=\"$(goma_dir)\"",
-    "target_cpu=\"arm\""
+    "target_cpu=\"arm\"",
+    "use_xcode_clang=true"
   ],
   "mb_type": "gn",
   "compiler": "ninja",
-  "additional_compile_targets": [ "gn_all" ],
   "configuration": "Release",
   "sdk": "iphoneos10.0",
   "tests": [