Technology drilldown - add a histogram view of the percentile breakdowns

[alonkochba]

Today the technology report is very ternary in nature - each CWV is just green/orange/red. The report focuses on what percentage of sites for a platform are green (either for all 3 CWVs, or each one separately).
It's not really possible to understand how close a platform is to transition from orange to green - for example a site with 2.6s LCP will be equivalent to one with 3.9s LCP (moderate), same for 2.4s LCP vs 0.5s LCP, something like this (but with nicer graphics and no bucket bugs)

HTTPArchive uses histograms in a few places, at least in the almanac. The data is there, should be relatively easy to visualize.
Treo does a nice job of visualizing such histograms (on a site level). In our case the distribution would be for the p75 of sites using the platform, instead of a distribution of a sites sessions.

[rviscomi]

I like the idea of providing more detailed histograms. There are a few challenges:

• they're inherently harder to grok than a single data point (ie % good) so we'd need to balance information density with usability
• they're harder to visualize over time so we would only be able to show the distribution for a single month
• Data Studio is limited in how it can switch between chart types so this feature might only be feasible in a hand-coded dashboard like the reports on httparchive.org