Align RenderObject's containingBlock / container

Align RenderObject's containingBlock / container

The 2 functions work similarly but they had a lot of tiny
differences for no good reason. This change makes them closer
in intended behavior and adds more code sharing.

While touching the code, I removed some very old comment that
didn't match the current code.

Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=162524

[Julien - ping for review, 2013-11-18 04:24:07]

@eseidel / @esprehn: Review ping!

[esprehn, 2013-11-22 05:19:08]

lgtm, one nit

https://codereview.chromium.org/64913004/diff/40001/Source/core/rendering/Ren...
File Source/core/rendering/RenderObject.cpp (right):

https://codereview.chromium.org/64913004/diff/40001/Source/core/rendering/Ren...
Source/core/rendering/RenderObject.cpp:810: while (ancestor) {
This can be a for loop, for (RenderObject* ancestor = parent(); ancestor;
ancestor = ancestor->parent())

[Julien - ping for review, 2013-11-22 07:06:49]

https://codereview.chromium.org/64913004/diff/40001/Source/core/rendering/Ren...
File Source/core/rendering/RenderObject.cpp (right):

https://codereview.chromium.org/64913004/diff/40001/Source/core/rendering/Ren...
Source/core/rendering/RenderObject.cpp:810: while (ancestor) {
On 2013/11/22 05:19:08, esprehn wrote:
> This can be a for loop, for (RenderObject* ancestor = parent(); ancestor;
> ancestor = ancestor->parent())

Changed to:

RenderObject* ancestor = parent();
for (; ancestor && !ancestor->canContainFixedPositionObjects(); ancestor =
ancestor->parent()) {

[We need ancestor defined in the function's scope and folded the following break
in the for]

[commit-bot: I haz the power, 2013-11-22 07:08:38]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/jchaffraix@chromium.org/64913004/140001

[commit-bot: I haz the power, 2013-11-22 08:26:25]

Change committed as 162524