Use IdTargetObserver in SVGFEImageElement

Use IdTargetObserver in SVGFEImageElement

Change SVGFEImageElement to use the observeTarget() helper from
SVGURIReference.
A slight change in behavior for when a load is initiated for a potential
image resource is made. Instead of using a "failed element lookup and a
non-existing id" as the condition, use "failed element lookup and non-
local resource reference".
Also add a new method clearImageResource() and put the tear-down for
the image resource, and change a use of ownerDocument() to just
document().

BUG=661598
Review-Url: https://codereview.chromium.org/2740003003
Cr-Commit-Position: refs/heads/master@{#455765}
Committed: https://chromium.googlesource.com/chromium/src/+/32a58c7e9cf5f455eb07420587efec657b1409ba

[fs, 2017-03-09 12:20:29]

The CQ bit was checked by fs@opera.com to run a CQ dry run

[commit-bot: I haz the power, 2017-03-09 12:20:42]

Dry run: CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2017-03-09 13:58:31]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2017-03-09 13:58:32]

Dry run: This issue passed the CQ dry run.

[fs, 2017-03-09 14:54:58]

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

[Stephen Chennney, 2017-03-09 15:38:18]

lgtm

[fs, 2017-03-09 16:26:54]

The CQ bit was checked by fs@opera.com

[commit-bot: I haz the power, 2017-03-09 16:27:41]

CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2017-03-09 16:37:34]

CQ is committing da patch.

Bot data: {"patchset_id": 20001, "attempt_start_ts": 1489076814029430,
"parent_rev": "ce79930d02031cfe9ba94249937643f99a2f55e8", "commit_rev":
"32a58c7e9cf5f455eb07420587efec657b1409ba"}

[commit-bot: I haz the power, 2017-03-09 16:39:24]

Description was changed from

==========
Use IdTargetObserver in SVGFEImageElement

Change SVGFEImageElement to use the observeTarget() helper from
SVGURIReference.
A slight change in behavior for when a load is initiated for a potential
image resource is made. Instead of using a "failed element lookup and a
non-existing id" as the condition, use "failed element lookup and non-
local resource reference".
Also add a new method clearImageResource() and put the tear-down for
the image resource, and change a use of ownerDocument() to just
document().

BUG=661598
==========

to

==========
Use IdTargetObserver in SVGFEImageElement

Change SVGFEImageElement to use the observeTarget() helper from
SVGURIReference.
A slight change in behavior for when a load is initiated for a potential
image resource is made. Instead of using a "failed element lookup and a
non-existing id" as the condition, use "failed element lookup and non-
local resource reference".
Also add a new method clearImageResource() and put the tear-down for
the image resource, and change a use of ownerDocument() to just
document().

BUG=661598

Review-Url: https://codereview.chromium.org/2740003003
Cr-Commit-Position: refs/heads/master@{#455765}
Committed:
https://chromium.googlesource.com/chromium/src/+/32a58c7e9cf5f455eb07420587ef...
==========

[commit-bot: I haz the power, 2017-03-09 16:39:25]

Committed patchset #2 (id:20001) as
https://chromium.googlesource.com/chromium/src/+/32a58c7e9cf5f455eb07420587ef...