New "Chromium Usage" column

[DanielRyanSmith]

Fixes #785

(WIP)

[jcscottiii]

You are on the right track.

For writing the playwright test: To quickly iterate on just your test, you may want to take a look at option 2 in this comment. This will prevent you from having to always run the whole test suite every time.

A few notes:

The all column CSV snapshot should have updated the values (not just the header).

Even though this is not a default column yet, you should still create a temporary test in overview-page.spec.ts.

If this was not a temporary thing, you would do the whole interaction where you click through the columns button and enable it (like here). But for this test, I think it is fair to just navigate directly to the page with the column enabled.

Something like this:

test('shows the usage column', async ({page}) => { 
    // Given that the usage column will graduate to be a default column, we will not do the interaction to enable it in the columns dialog like we normally would. Instead, we will navigate straight to the page with it enabled.
    // TODO remove this test once the usage column is enabled by default
    await gotoOverviewPageUrl(page, 'http://localhost:5555/?columns=name%2Cbaseline_status%2Cstable_chrome%2Cstable_edge%2Cstable_firefox%2Cstable_safari%2Cchromium_usage');
    // Take screenshot
});

[jcscottiii]

Also, you may want to take a look at how chromestatus displays the data. We get the same data in the same format.

https://github.com/search?q=repo%3AGoogleChrome%2Fchromium-dashboard%20day_percentage&type=code

[DanielRyanSmith]

I'm not certain what happened here, but my newest commits stopped updating this PR and were only available locally (almost certainly due to a novice mistake on my end).

I went ahead and cherry-picked all my changes, and they're now available at #907, so I'm just going to close this PR for now.