Move paint code from RenderSVGForeignObject to SVGForeignObjectPainter

Move paint code from RenderSVGForeignObject to SVGForeignObjectPainter

This patch moves the ForeignObject paint code into the new
SVGForeignObjectPainter. This is a straight code move with a few small
exceptions:
1) childPoint is now const and is used for all BlockPainter calls.
Previously, an extra IntPoint() was used for no reason.
2) FloatRect viewportRect() has been exposed on RenderSVGForeignObject.
3) Fixed up a comment.

BUG=412088
Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=182540

[pdr., 2014-09-23 23:23:02]

pdr@chromium.org changed reviewers:
+ chrishtr@chromium.org, leviw@chromium.org

[pdr., 2014-09-23 23:24:30]

Chris seemed lonely over in core/paint/ so I made him a new SVG friend.

[chrishtr, 2014-09-23 23:27:48]

I think you missed adding the new classes.

[pdr., 2014-09-23 23:28:38]

On 2014/09/23 23:27:48, chrishtr wrote:
> I think you missed adding the new classes.

Fixed (oops!)

[chrishtr, 2014-09-23 23:29:12]

lgtm

[chrishtr, 2014-09-23 23:29:16]

The CQ bit was checked by chrishtr@chromium.org

[commit-bot: I haz the power, 2014-09-23 23:30:18]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/597753002/20001

[commit-bot: I haz the power, 2014-09-24 00:44:50]

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

[commit-bot: I haz the power, 2014-09-24 00:44:52]

Try jobs failed on following builders:
  mac_blink_rel on tryserver.blink
(http://build.chromium.org/p/tryserver.blink/builders/mac_blink_rel/builds/24463)

[pdr., 2014-09-24 00:46:25]

The CQ bit was checked by pdr@chromium.org

[commit-bot: I haz the power, 2014-09-24 00:47:48]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/597753002/20001

[commit-bot: I haz the power, 2014-09-24 01:31:30]

Committed patchset #2 (id:20001) as 182540