This answer below is based on the answer to a question asked at stackoverflow: What is following header for: X-Chrome-Variations?.
To improve the performance of the browser, Google tries new ideas out in the real world to discover useful features. These are called Field Trials.
The "Variations" section seen in the output of
chrome://version is a part of Google's Field Trials. Users of the Release version of the Chrome browser can see a series of hash-hash pairs in the "Variations" section of
chrome://version since Chrome 23.
More information on the purpose of Chrome Variations can be found in Google Chrome Privacy Whitepaper; the relevant section is quoted below:
To help guide the construction of features that users actually find useful, a subset of users may get a sneak peek at new functionality before it’s launched to the world at large. The field trials that are currently active on your installation of Chrome will be included in all requests sent to Google servers to allow Google to filter logs for only those generated by a given variation of Chrome. This Chrome-Variations header will not contain any personally identifiable information, and will strictly describe the state of the installation of Chrome itself.
The variations active for a given installation are determined by a seed number between 1 and 8192 (13 bits of entropy) which is randomly selected on first run. If you would like to reset your variations seed, run Chrome with the command line flag