Fix const correctness of containerForRepaint

Fix const correctness of containerForRepaint

Working on https://codereview.chromium.org/264183002/ I ran
into some const correctness issues with the fact that containerForRepaint
returns a non-const pointer, despite repaint being a const operation.
Fixing this before landing that patch.

BUG=320139
Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=173585

[leviw_travelin_and_unemployed, 2014-05-07 22:42:48]

Figured I'd start with this one.

[Julien - ping for review, 2014-05-07 22:55:41]

lgtm

https://codereview.chromium.org/276583002/diff/1/Source/core/rendering/Render...
File Source/core/rendering/RenderObject.h (right):

https://codereview.chromium.org/276583002/diff/1/Source/core/rendering/Render...
Source/core/rendering/RenderObject.h:831: const LayoutRect& oldBounds, const
LayoutPoint& oldPositionFromRepaintContainer, const LayoutRect* newBoundsPtr =
0, const LayoutPoint* newPositionFromRepaintContainer = 0) const;
I am on the fence about that. While it is true that we don't modify RenderObject
in this function now, it doesn't mean that we won't in the future or that it's
wrong in the long run.

If that's not required by some of your 'const' change, I would just ignore that
part for now.

[leviw_travelin_and_unemployed, 2014-05-07 22:56:59]

On 2014/05/07 22:55:41, Julien Chaffraix - PST wrote:
> lgtm
> 
>
https://codereview.chromium.org/276583002/diff/1/Source/core/rendering/Render...
> File Source/core/rendering/RenderObject.h (right):
> 
>
https://codereview.chromium.org/276583002/diff/1/Source/core/rendering/Render...
> Source/core/rendering/RenderObject.h:831: const LayoutRect& oldBounds, const
> LayoutPoint& oldPositionFromRepaintContainer, const LayoutRect* newBoundsPtr =
> 0, const LayoutPoint* newPositionFromRepaintContainer = 0) const;
> I am on the fence about that. While it is true that we don't modify
RenderObject
> in this function now, it doesn't mean that we won't in the future or that it's
> wrong in the long run.
> 
> If that's not required by some of your 'const' change, I would just ignore
that
> part for now.

Good point. Thanks!

[leviw_travelin_and_unemployed, 2014-05-07 23:01:51]

The CQ bit was checked by leviw@chromium.org

[commit-bot: I haz the power, 2014-05-07 23:02:36]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/leviw@chromium.org/276583002/20001

[leviw_travelin_and_unemployed, 2014-05-07 23:55:08]

The CQ bit was checked by leviw@chromium.org

[commit-bot: I haz the power, 2014-05-07 23:55:52]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/leviw@chromium.org/276583002/40001

[commit-bot: I haz the power, 2014-05-08 01:05:11]

Change committed as 173585