Eliminate SVGUseElement::referencedScope()

Eliminate SVGUseElement::referencedScope()

During "shadow tree fixup" (SVGUseElement::expand*) we can use the
document of the original (corresponding) element rather than
referencedScope(), because the Document of those elements will be the
external or the "local" respectively depending on source for the initial
clone operation.
This leaves a few users in buildPendingResource() which can be
eliminated by folding the method into it.
Hopefully this will also allow future cleanups to
isExternalURIReference, since now it's not called unnecessarily for each
nested <use>. (Possibly minor perf effect from eliminating the calls to
referencedScope().)

BUG=589682
Committed: https://crrev.com/c427062580ade2dde463ff0c51f33717099e6c9c
Cr-Commit-Position: refs/heads/master@{#379074}

[fs, 2016-03-03 17:57:02]

fs@opera.com changed reviewers:
+ pdr@chromium.org, schenney@chromium.org

[pdr., 2016-03-03 19:39:47]

On 2016/03/03 at 17:57:02, fs wrote:
> 

LGTM

[fs, 2016-03-03 20:27:53]

The CQ bit was checked by fs@opera.com

[commit-bot: I haz the power, 2016-03-03 20:28:34]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1757323002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1757323002/1

[commit-bot: I haz the power, 2016-03-03 20:35:53]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-03-03 20:37:12]

Description was changed from

==========
Eliminate SVGUseElement::referencedScope()

During "shadow tree fixup" (SVGUseElement::expand*) we can use the
document of the original (corresponding) element rather than
referencedScope(), because the Document of those elements will be the
external or the "local" respectively depending on source for the initial
clone operation.
This leaves a few users in buildPendingResource() which can be
eliminated by folding the method into it.
Hopefully this will also allow future cleanups to
isExternalURIReference, since now it's not called unnecessarily for each
nested <use>. (Possibly minor perf effect from eliminating the calls to
referencedScope().)

BUG=589682
==========

to

==========
Eliminate SVGUseElement::referencedScope()

During "shadow tree fixup" (SVGUseElement::expand*) we can use the
document of the original (corresponding) element rather than
referencedScope(), because the Document of those elements will be the
external or the "local" respectively depending on source for the initial
clone operation.
This leaves a few users in buildPendingResource() which can be
eliminated by folding the method into it.
Hopefully this will also allow future cleanups to
isExternalURIReference, since now it's not called unnecessarily for each
nested <use>. (Possibly minor perf effect from eliminating the calls to
referencedScope().)

BUG=589682

Committed: https://crrev.com/c427062580ade2dde463ff0c51f33717099e6c9c
Cr-Commit-Position: refs/heads/master@{#379074}
==========

[commit-bot: I haz the power, 2016-03-03 20:37:13]

Patchset 1 (id:??) landed as
https://crrev.com/c427062580ade2dde463ff0c51f33717099e6c9c
Cr-Commit-Position: refs/heads/master@{#379074}