It is possible in extreme cases that the Telemetry IPC Accumulator might be
starved long enough that it cannot drain its stored accumulations for a while.
Once we hit 5x the high water mark, start discarding data.
Count each piece and type of discarded data and report it via a custom IPC
message.
MozReview-Commit-ID: JayRpa5QPec
Changed |print("enum ID : uint32_t {", file=output)| to |print("enum HistogramID : uint32_t {", file=output)| at line 53 of the file |toolkit/components/telemetry/gen-histogram-enum.py|, and then replaced all the textual occurrences of |Telemetry::ID| to |Telemetry::HistogramID| and |ID| to |HistogramID| in 43 other files.
