Mac app store build uses non-public APIs 
* Electron version: 1.5.0
* Operating system: macOS

I made a test build with the electron 1.5.0 MAS version and submitted it to apple. These are the issues that apple complained about.

> Performance - 2.5.1
>
> Your app uses or references the following non-public API(s):
>
> '/System/Library/Frameworks/CoreGraphics.framework/Versions/A/CoreGraphics'
>
> : CGSSetWindowBackgroundBlurRadius
>
> The use of non-public APIs is not permitted on the App Store as it can lead to a poor user experience should these APIs change.

diff --git a/script/lib/config.py b/script/lib/config.py
index 96c6591a54..d3f2c33d4c 100644
--- a/script/lib/config.py
+++ b/script/lib/config.py
@@ -9,7 +9,7 @@ import sys
 BASE_URL = os.getenv('LIBCHROMIUMCONTENT_MIRROR') or \\
     'https://s3.amazonaws.com/github-janky-artifacts/libchromiumcontent'
 LIBCHROMIUMCONTENT_COMMIT = os.getenv('LIBCHROMIUMCONTENT_COMMIT') or \\
-    'ea20b8dfe0a7fad61bb4917404950ddcd2224588'
+    '4f5b89374df7ee69095b9f7d50b30fb46ddd7407'
 
 PLATFORM = {
   'cygwin': 'win32',
['script/lib/config.py']