Bugzilla

I retested, and  I sometimes get "good" profiles where the resizes are pretty smooth. And sometimes I get "bad" profiles where the resizes take a looooong time. No idea why there would be this dual behaviour.

Good: https://share.firefox.dev/3Xh3li0
Bad: https://share.firefox.dev/3YWGcCN (loooong time)

I retested, and  I sometimes get "good" profiles where the resizes are pretty smooth. And sometimes I get "bad" profiles where the resizes take a looooong time. No idea why there would be this dual behaviour.

Good: https://share.firefox.dev/3Xh3li0
Bad: https://share.firefox.dev/3YWGcCN (loooong time)

Edit: In this profile, it was initially very smooth. But then it became very slow.
https://share.firefox.dev/3z26Qzv

This may be that if you continue to resize without letting go of the resize handle, it will be fast. But if you release the handle (and myabe switch tabs) and then retry, the reflows are slow?

I retested, and  I sometimes get "good" profiles where the resizes are pretty smooth. And sometimes I get "bad" profiles where the resizes take a looooong time. No idea why there would be this dual behaviour.

Good: https://share.firefox.dev/3Xh3li0
Bad: https://share.firefox.dev/3YWGcCN (loooong time)

Edit: In this profile, it was initially very smooth. But then it became very slow.
https://share.firefox.dev/3z26Qzv

This may be that if you continue to resize without letting go of the resize handle, it will be fast. But if you release the handle (and myabe switch tabs) and then retry, the reflows are slow? Almost like doing an action inadvertently flushes away some cache.