Well, I use Ubuntu GNU/Linux, and Chromium as my primary browser, and never tried Chrome in Linux. So, for Chromium in Linux I have an answer and I think It should be same for Chrome too. Apparently you can refer this link for Windows Platform.
So, Default Preferences for Chromium Browser in Linux are saved in (See this)
It is much similar to
for customizing Default Preferences in Mozilla Firefox but don't know whether It's a
.js file or not.
Preferences file looks like this. It looks a kind of messy, So, I thought to indent it to make some sense. To view Formmated
file Click here. It stores the each preference in the comma separated values where each preference is written in form of JSON Markup
" Preference name " : " value "
Apart from this, in the same folder, there is also a file named "Secure Preferences" that stores only one preference.
As far as programming the preferences are concerned, Chromium Project Page specifies the differences between the Ploicies & Preferences, and also suggests to write ploicies instead of preferences beacuse Policies take precedence to preferences. If "homepage" is specified in both the policies, and in the "master_preferences" file, policies will always override.
You can edit Preferences for the Browser as stated in these pages :
The Chromium Project Page :: Configuring Other Preferences :
Under the Section Preferences vs. Policies - 3rd bullet point under Preferences.
The Chromium Project Page :: Preferences : Under the Section Introduction - 6th line. Also this particular page explains pretty much everything you need to do to set preferences programmatically. I am sure that will work for you.
For just a little Reference, See this post by sputnam, in which he shows a sample of Preferences Code edited by him.