Cleanup: Only need one bit (not two) to express flow thread state.

Cleanup: Only need one bit (not two) to express flow thread state.

The InsideOutOfFlowThread / InsideInFlowThread distinction is a relic from the
CSS Regions days. Just telling whether we're a descendant of a flow thread or
not is enough.

R=dsinclair@chromium.org

Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=194945

[mstensho (USE GERRIT), 2015-05-05 19:09:09]

https://codereview.chromium.org/1124993002/diff/1/Source/core/layout/LayoutOb...
File Source/core/layout/LayoutObject.h (right):

https://codereview.chromium.org/1124993002/diff/1/Source/core/layout/LayoutOb...
Source/core/layout/LayoutObject.h:1316: // 32 bits have been used in the first
word, and 14 in the second.
Note: I counted the bits over and over again, and came to the conclusion that
there used to be 15 bits in the second word, not 14. But _now_ there's going to
be 14. :)

[dsinclair, 2015-05-05 19:09:21]

The CQ bit was checked by dsinclair@chromium.org

[dsinclair, 2015-05-05 19:09:21]

lgtm

[commit-bot: I haz the power, 2015-05-05 19:09:52]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1124993002/1

[commit-bot: I haz the power, 2015-05-05 22:21:32]

Committed patchset #1 (id:1) as
https://src.chromium.org/viewvc/blink?view=rev&revision=194945