UserAgent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/55.0.2883.87 Safari/537.36

Steps to reproduce the problem:
1. Open the network tab in dev tools
2. Load a page
3. Observe an HTTP request that wasn't served by cache

What is the expected behavior?
For each resource, there should be some way to determine why the resource was not loaded from cache.  The reasons why could be any one of many, such as:

-No matching key in cache
-Existing cache has expired
-SSL/Certificate error preventing use of cache
-Cache-Control flag prevents caching
-Some other HTTP header prevents caching

What went wrong?
New enhancement request

Did this work before? N/A 

Chrome version: 55.0.2883.87  Channel: stable
OS Version: 
Flash Version: Shockwave Flash 24.0 r0