Add Traversal<>::firstAncestorOrSelf() overload taking a const reference in argument

Add Traversal<>::firstAncestorOrSelf() overload taking a const reference in argument

Add Traversal<>::firstAncestorOrSelf() overload taking a const reference in
argument, and returning a const pointer. Make use of this new function in
Element::rendererIsFocusable().

R=esprehn@chromium.org, adamk@chromium.org

Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=178504

[adamk, 2014-07-18 23:39:14]

Seems like a small win (and I'm not clear on why you need both Element and Node
overrides), but lgtm

[Inactive, 2014-07-19 00:02:54]

Sorry, I know this is a small change. I split this out of a bigger patch to
reduce the diff and make it more easily reviewable.

https://codereview.chromium.org/397303005/diff/1/Source/core/dom/ElementTrave...
File Source/core/dom/ElementTraversal.h (right):

https://codereview.chromium.org/397303005/diff/1/Source/core/dom/ElementTrave...
Source/core/dom/ElementTraversal.h:194: if (isElementOfType<const
ElementType>(current))
The reason there is an Element overload is to avoid an unnecessary
isElementNode() check in isElementOfType<>() when the input is an Element (and
not a Node).

[adamk, 2014-07-19 00:04:07]

On 2014/07/19 at 00:02:54, ch.dumez wrote:
> Sorry, I know this is a small change. I split this out of a bigger patch to
reduce the diff and make it more easily reviewable.

Ah, that makes more sense. Sounds good.

[Inactive, 2014-07-19 00:20:14]

The CQ bit was checked by ch.dumez@samsung.com

[commit-bot: I haz the power, 2014-07-19 00:21:05]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/ch.dumez@samsung.com/397303005/1

[commit-bot: I haz the power, 2014-07-19 00:31:09]

Change committed as 178504