Version: 55.0.2847.0
OS: Windows 7

What steps will reproduce the problem?
(1) Visit http://files.unity3d.com/alexsuvorov/bugs/chrome-revalidation/
(2) Click GET button a few times
(3) Open DevTools Network panel
(4) Observe only first click on GET shows an item in the Dev Tools Network request list
(5) Ensure Disable Cache checkbox is ticked
(6) Observe only first click after setting disable cache shows an item in the Dev Tools Network request list. Subsequent requests return cached results.

What is the expected output?
When "Disable Cache" is set, memory cache is not hit

What do you see instead?
"Disable Cache" does not disable the memory cache, it simply clears it one time (https://cs.chromium.org/chromium/src/third_party/WebKit/Source/core/inspector/InspectorNetworkAgent.cpp?q=cacheDisabled&sq=package:chromium&l=1126&dr=CSs) with a call to memoryCache()->evictResources();
 
[Possible fix]
Add to InspectorNetworkAgent::willSendRequest() the lines:

  if (m_state->booleanProperty(NetworkAgentState::cacheDisabled, false))
    memoryCache()->evictResources();