Thumbnail changes update the tabs tray too often

[jonalmeida]

When we update the tabs tray, we use the generationId from the bitmap to identify if the thumbnails have changed. It turns out that these are not stable (probably because we're compressing the images so the ID changes).

We need a better way to avoid the whole tray from updating when we have a thumbnail update.

┆Issue is synchronized with this Jira Task

[jonalmeida]

Possible duplicates/fallout:

• [Bug] Tab Tray - Grey Screenshots After Sharing Tabs fenix#11156
• [Bug]Tab Tray: Flicker after undoing the deletion of all open tabs fenix#10730
• Swipe to delete on tab with thumbnail makes it show up for a brief second #7282
• [Bug] Long delay when swiping to close tabs with many tabs open (~100 tabs) fenix#11352

[jonalmeida]

I verified that removing the generationId from Tabs.equals causes the multiple refreshes.

In mozilla-mobile/fenix#11185 (comment), I mentioned we should try to use the loadToView mechanism to show the icons safely. I now think that's probably the best way forward for this problem too. It would solve:

• The initial case where you want to load the initial image from the disk.
• We can remove the use case mapping from the TabsTrayPresenter
• For thumbnail updates, we forward the new thumbnails into the presenter and save them async for the next time we need to load fresh thumbnails from disk.

What changes though is the surface area of this API for the consumer to load the thumbnails where ever the caller needs.

More concretely, the ThumbnailsStorage should add a method like loadIntoView and call that on the viewholder when binding, and update the viewholder as well if new changes come from the store.