UserAgent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/68.0.3440.106 Safari/537.36

Steps to reproduce the problem:
0. Have Linux with Chromium

1. Create ext1.json and ext2.json files in /etc/chromium/policies/managed
2. Let ext1.json have ExtensionInstallForcelist and install Extension1

{ "ExtensionInstallForcelist":[ "aaaabbbbcccc;file:///path/ext1.xml" ] }

3. Let ext2.json have ExtensionInstallForcelist and install Extension2

{ "ExtensionInstallForcelist":[ "ddddeeeeffff;file:///path/ext2.xml" ] }

4. Restart Chromium

What is the expected behavior?
Both Extension1 and Extension2 should be installed in Chromium, but only Extension2 is installed.

What went wrong?
Policy ExtensionInstallForcelist from ext2.json overrides ExtensionInstallForcelist from ext1.json.
The problem is, ExtensionInstallForcelist policies should be merged but they aren't, this makes things difficult to distribute two addons  in separate packages.

Did this work before? N/A 

Chrome version: 68.0.3440.106  Channel: stable
OS Version: 4.17
Flash Version: none