Fills do not render after adding two image sources & layers

[lucaswoj]

mapbox-gl-js version: v0.26.0

Steps to Trigger Behavior

http://jsbin.com/niqekeduni/edit?html,output

Expected Behavior

The dark-v9 style is visible.

Actual Behavior

This 👇

[lucaswoj]

What I know at this point:

• the bug occurs more often in some environments than others
• the bug does not occur before caa1216 / DRY up VideoSource code #3353
• the same underlying issue is causing the image/default mapbox-gl-test-suite test to fail
  • I suspect the same underlying issue because both begin failing in caa1216
• the bug occurs in test-suite with 1 image source but requires 2 image sources to occur in the browser
• the bug only occurs in test-suite in the first image source test, regardless of what that test is
• the bug goes away as soon as the map is interacted with (panned, zoomed, resized, etc)
• there is another bug that seems to have a different root cause which causes the animation loop to stop before a raster layer has completely faded in

[lucaswoj]

Fixed in #3522!