Introduce toSVGUseElement(), use it

Introduce toSVGUseElement(), use it

As a step to change static_cast with toSVGXXX, static_cast<SVGUseElement*> can
be changed with toSVGUseElement().

BUG=

Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=154609

[gyuyoung-inactive, 2013-07-18 05:46:07]

Add tkent as reviewer.

[tkent, 2013-07-18 05:50:07]

lgtm

[commit-bot: I haz the power, 2013-07-18 05:50:18]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/gyuyoung.kim@samsung.com/19539003/1

[commit-bot: I haz the power, 2013-07-18 06:04:07]

Sorry for I got bad news for ya.
Compile failed with a clobber build on linux_layout.
http://build.chromium.org/p/tryserver.chromium/buildstatus?builder=linux_layo...
Your code is likely broken or HEAD is junk. Please ensure your
code is not broken then alert the build sheriffs.
Look at the try server FAQ for more details.

[gyuyoung-inactive, 2013-07-18 23:09:39]

On 2013/07/18 06:04:07, I haz the power (commit-bot) wrote:
> Sorry for I got bad news for ya.
> Compile failed with a clobber build on linux_layout.
>
http://build.chromium.org/p/tryserver.chromium/buildstatus?builder=linux_layo...
> Your code is likely broken or HEAD is junk. Please ensure your
> code is not broken then alert the build sheriffs.
> Look at the try server FAQ for more details.


Let me check what is bad.

[gyuyoung-inactive, 2013-07-18 23:37:00]

On 2013/07/18 23:09:39, gyuyoung wrote:
> On 2013/07/18 06:04:07, I haz the power (commit-bot) wrote:
> > Sorry for I got bad news for ya.
> > Compile failed with a clobber build on linux_layout.
> >
>
http://build.chromium.org/p/tryserver.chromium/buildstatus?builder=linux_layo...
> > Your code is likely broken or HEAD is junk. Please ensure your
> > code is not broken then alert the build sheriffs.
> > Look at the try server FAQ for more details.
> 
> 
> Let me check what is bad.

Oops, build break came from debug buildbot. I will upload fixed patch. Sorry
about it.

[gyuyoung-inactive, 2013-07-19 02:20:45]

On 2013/07/18 23:37:00, gyuyoung wrote:
> On 2013/07/18 23:09:39, gyuyoung wrote:
> > On 2013/07/18 06:04:07, I haz the power (commit-bot) wrote:
> > > Sorry for I got bad news for ya.
> > > Compile failed with a clobber build on linux_layout.
> > >
> >
>
http://build.chromium.org/p/tryserver.chromium/buildstatus?builder=linux_layo...
> > > Your code is likely broken or HEAD is junk. Please ensure your
> > > code is not broken then alert the build sheriffs.
> > > Look at the try server FAQ for more details.
> > 
> > 
> > Let me check what is bad.
> 
> Oops, build break came from debug buildbot. I will upload fixed patch. Sorry
> about it.

Build error is fixed.

[commit-bot: I haz the power, 2013-07-19 02:29:45]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/gyuyoung.kim@samsung.com/19539003/15001

[commit-bot: I haz the power, 2013-07-19 02:41:25]

Retried try job too often on linux_blink_rel for step(s) webkit_lint,
webkit_python_tests, webkit_tests, webkit_unit_tests, weborigin_unittests,
wtf_unittests
http://build.chromium.org/p/tryserver.chromium/buildstatus?builder=linux_blin...

[commit-bot: I haz the power, 2013-07-19 03:36:58]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/gyuyoung.kim@samsung.com/19539003/15001

[commit-bot: I haz the power, 2013-07-19 04:41:11]

Retried try job too often on linux_blink_rel for step(s) webkit_lint,
webkit_python_tests, webkit_tests, webkit_unit_tests, weborigin_unittests,
wtf_unittests
http://build.chromium.org/p/tryserver.chromium/buildstatus?builder=linux_blin...

[commit-bot: I haz the power, 2013-07-19 08:15:30]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/gyuyoung.kim@samsung.com/19539003/15001

[commit-bot: I haz the power, 2013-07-19 08:24:45]

Retried try job too often on linux_blink_rel for step(s) webkit_lint,
webkit_python_tests, webkit_tests, webkit_unit_tests, weborigin_unittests,
wtf_unittests
http://build.chromium.org/p/tryserver.chromium/buildstatus?builder=linux_blin...

[commit-bot: I haz the power, 2013-07-19 10:16:27]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/gyuyoung.kim@samsung.com/19539003/15001

[commit-bot: I haz the power, 2013-07-20 09:47:29]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/gyuyoung.kim@samsung.com/19539003/38001

[commit-bot: I haz the power, 2013-07-20 13:28:05]

Retried try job too often on win_blink_rel for step(s) webkit_tests
http://build.chromium.org/p/tryserver.chromium/buildstatus?builder=win_blink_...

[commit-bot: I haz the power, 2013-07-21 09:00:31]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/gyuyoung.kim@samsung.com/19539003/38001

[commit-bot: I haz the power, 2013-07-21 09:43:11]

Change committed as 154609