Get a minimal all.gyp working for iOS

build/common.gypi

Index: build/common.gypi
diff --git a/build/common.gypi b/build/common.gypi
index 401ceb298b4bf22f978b2019300220f0747dd898..b037a41f19b60e3cd80b252dcbf3a9cbe4f73de9 100644
--- a/build/common.gypi
+++ b/build/common.gypi
@@ -445,6 +445,11 @@
           'enable_webrtc%': 0,
         }],
 
+        ['OS=="ios"', {
+          'enable_automation%': 0,
+          'remoting%': 0,
+        }],
+
         # Use GPU accelerated cross process image transport by default
         # on linux builds with the Aura window manager
         ['use_aura==1 and OS=="linux"', {
@@ -835,6 +840,9 @@
           }],
         ],
       }],  # os_posix==1 and OS!="mac" and OS!="ios"
+      ['OS=="ios"', {
+        'disable_nacl%': 1,
+      }],
       ['OS=="android"', {
         # Location of Android NDK.
         'variables': {