1382703 - Firefox seems to be loading twitter in the background on startup for no apparent reason

Status: RESOLVED FIXED

(Firefox :: New Tab Page, defect)

Description

[Kartikaya Gupta (email:[e-mail])]

Local opt build on OS X, latest m-c code. Modify modules/libpref/init/all.js so that the pref "layout.display-list.dump-content" is true by default. This will dump the display lists of documents that we're painting in content processes.

Start on a clean profile like so:
  ./mach run about:blank 2>&1 | tee startup.log
and wait for a bit (~15-20 seconds) until the console output stops rolling

Since this is on a clean profile, there are two tabs loaded: one (the foreground) is about:blank as specified on the command line. The second (background) is https://www.mozilla.org/en-US/privacy/firefox/.

However, if you look in startup.log, you'll see that a document that looks suspiciously like twitter.com also got painted. You can search for the string "New to Twitter?" to find it in the output. Neither about:blank nor the mozilla privacy page load any content from twitter.com so this must be getting loaded from somewhere else. It seems rather undesirable, specially considering the content is not actually painted to the screen - we shouldn't be building a display list for it, or loading it at all really.

Comment 1

[Kartikaya Gupta (email:[e-mail])]

Attachment: startup.log

Here's the startup.log that I generated using the STR.

Comment 2

[:Gijs (he/him)]

I'm pretty sure this is for the screenshots for the tiles on the new tab page. See https://dxr.mozilla.org/mozilla-release/source/toolkit/components/thumbnails/BackgroundPageThumbs.jsm and friends.

Comment 3

[Kartikaya Gupta (email:[e-mail])]

Ah ok.

Comment 4

[:Gijs (he/him)]

(In reply to Kartikaya Gupta (email:[e-mail]) from comment #3)
> Ah ok.

Wellll, I mean, it's still not great for first startup on a clean profile. I think this didn't use to be a problem because the default tiles we shipped to users were all 'enhanced' so they had their own custom images and we didn't fetch anything for them. Activity stream changed that.

I think we should at least consider shipping placeholder images for these domains to avoid downloading several MB of data on first startup and doing all the associated rendering. Maybe this is already on the Activity Stream folks' radar?

Comment 5

[Ed Lee :Mardak]

I believe we can package those images now that bug 1374898 is resolved.

Comment 6

[Tim Spurway [:tspurway]]

Just to re-iterate the plan here.  We will include the metadata for default topsites in the build.  This will allow us to avoid unnecessary network calls, while supplying excellent quality icons for the 'first run' users (or other newish profiles).

Comment 7

[Ed Lee :Mardak]

Fixed with https://github.com/mozilla/activity-stream/pull/3049 to be uplifted via bug 1386314.