DataReductionProxy.ConfigService.HTTPRequests records whether the data reduction proxy (DRP) config was available at the time the HTTP request was made.

However, currently DataReductionProxy.ConfigService.HTTPRequests is not recorded precisely.
It should not be recorded when:
(1) Chrome is in data reduction proxy holdback experiment.
(2) URL is a local host URL.

Further, currently a false sample is recorded when DRP was not used even if the config service had already provided the proxy config. Instead, in those cases, a true sample should be recorded.