layout: Don't delete non-text boxes from the list of input boxes when

[pcwalton]

flushing text clumps. Fixes this page:

http://en.wikipedia.org/wiki/Yellow_River

This is not the most efficient thing to do; a FIXME has been added
noting what is most correct.

r? @jdm

[highfive]

Warning

• These commits modify layout code, but no reftests are modified. Please consider adding a reftest!
• @pcwalton, please confirm that src/test/html/acid1.html and your favourite wikipedia page still render correctly!

[pcwalton]

See #1319

[jdm]

r+

[bors-servo]

saw approval from jdm
at pcwalton@dcacab8

[bors-servo]

merging pcwalton/servo/bogus-box-deletion = dcacab8 into auto

[bors-servo]

pcwalton/servo/bogus-box-deletion = dcacab8 merged ok, testing candidate = acb3d9f

[bors-servo]

all tests pass:
success: http://servo-buildbot.pub.build.mozilla.org/builders/linux/builds/704
success: http://servo-buildbot.pub.build.mozilla.org/builders/mac/builds/659

[bors-servo]

fast-forwarding master to auto = acb3d9f