This name is only used for a DCHECK. Having it as a parameter leads to unnecessary string copying even on release builds.
This CL instead adds a GetHistogramName function that is only called on debug builds.
Checking if pointer is null is also moved outside HistogramAdd function. Having it there is confusing since Chromium implementation doesn't have it there.
BUG=webrtc:6329
Review-Url: https://codereview.webrtc.org/2337883003
Cr-Commit-Position: refs/heads/master@{#14263}
Only has counts stats right now but enumeration stats can easily be added in the future if needed.
BUG=webrtc:6313
Review-Url: https://codereview.webrtc.org/2320473002
Cr-Commit-Position: refs/heads/master@{#14146}
Updated tests to use the default implementation and removed the test implementation (webrtc/test/histograms.h).
BUG=
Review-Url: https://codereview.webrtc.org/1915523002
Cr-Commit-Position: refs/heads/master@{#12829}
