Let the RenderFlowThread layer have an empty size.

Let the RenderFlowThread layer have an empty size.

The RenderFlowThread has a RenderLayer used as a helper for painting. The
layer got its bounds from the RenderFlowThread contents which is typically
a tall strip and not the size of the area that where the contents are
rendered. That resulted in unnecessarily expanding the height of the parent
RenderLayer backing. The MultiColumnSet already contributes the correct
sizes, thus we can return an empty bounding rectangle for the layer of the
RenderFlowThread.

R=mstensho@opera.com
BUG=418899
Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=182906

[mstensho (USE GERRIT), 2014-09-30 09:10:20]

non-owner lgtm with nits.

https://codereview.chromium.org/612363002/diff/1/Source/core/rendering/Render...
File Source/core/rendering/RenderLayer.cpp (right):

https://codereview.chromium.org/612363002/diff/1/Source/core/rendering/Render...
Source/core/rendering/RenderLayer.cpp:3150: // The layer created for the
RenderFlowThread is just a helper for painting and should not
painting and hit-testing

https://codereview.chromium.org/612363002/diff/1/Source/core/rendering/Render...
Source/core/rendering/RenderLayer.cpp:3152: // size for the rendered content of
the flow thread.
s/flow thread/multicol container/

[rune, 2014-09-30 09:16:19]

https://codereview.chromium.org/612363002/diff/1/Source/core/rendering/Render...
File Source/core/rendering/RenderLayer.cpp (right):

https://codereview.chromium.org/612363002/diff/1/Source/core/rendering/Render...
Source/core/rendering/RenderLayer.cpp:3150: // The layer created for the
RenderFlowThread is just a helper for painting and should not
On 2014/09/30 09:10:20, mstensho wrote:
> painting and hit-testing

Done.

https://codereview.chromium.org/612363002/diff/1/Source/core/rendering/Render...
Source/core/rendering/RenderLayer.cpp:3152: // size for the rendered content of
the flow thread.
On 2014/09/30 09:10:20, mstensho wrote:
> s/flow thread/multicol container/

Done.

[rune, 2014-09-30 09:18:43]

The CQ bit was checked by rune@opera.com

[commit-bot: I haz the power, 2014-09-30 09:19:36]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/612363002/20001

[commit-bot: I haz the power, 2014-09-30 10:38:05]

Committed patchset #2 (id:20001) as 182906