Add support for the simple case of shape-margin polygonal shape-outside

BUG=228782
Add support for computing the shape-outside shape-margin boundary for a polygon. This change is similar to the one added for padding polygons, see bug https://bugs.webkit.org/show_bug.cgi?id=112592. The algorithm used for computing the margin boundary is is provisional. It works correctly for convex polygons and will work correctly for non self-intersecting polygons whose margin boundary is the same shape as the original polygon.

Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=148839

[Hans Muller, 2013-04-22 15:18:42]

I'd appreciate a review of this change.  It's just a WebKit sync-up patch.

[eseidel, 2013-04-22 16:01:26]

lgtm

The OwnPtr usage (since it clearly extends beyond this patch) can be done in a
second pass.  But this code really should use smart pointers to avoid leaks. :)

https://codereview.chromium.org/14220005/diff/1/Source/core/rendering/Exclusi...
File Source/core/rendering/ExclusionPolygon.cpp (left):

https://codereview.chromium.org/14220005/diff/1/Source/core/rendering/Exclusi...
Source/core/rendering/ExclusionPolygon.cpp:147: return new
FloatPolygon(adoptPtr(paddedVertices), fillRule);
Also PassOwnPtr.

https://codereview.chromium.org/14220005/diff/1/Source/core/rendering/Exclusi...
Source/core/rendering/ExclusionPolygon.cpp:151: static inline FloatPolygon
*computeShapeMarginBounds(const FloatPolygon& polygon, float margin, WindRule
fillRule)
* goes next to the type in WK style.

https://codereview.chromium.org/14220005/diff/1/Source/core/rendering/Exclusi...
Source/core/rendering/ExclusionPolygon.cpp:158: return new
FloatPolygon(adoptPtr(marginVertices), fillRule);
This needs to return a PassOwnPtr for the same reason.

https://codereview.chromium.org/14220005/diff/1/Source/core/rendering/Exclusi...
File Source/core/rendering/ExclusionPolygon.cpp (right):

https://codereview.chromium.org/14220005/diff/1/Source/core/rendering/Exclusi...
Source/core/rendering/ExclusionPolygon.cpp:154: Vector<FloatPoint>*
marginVertices = new Vector<FloatPoint>();
Please use an OwnPtr so this doens't get accidentally leaked.

[commit-bot: I haz the power, 2013-04-22 16:54:52]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/hmuller@adobe.com/14220005/5001

[Hans Muller, 2013-04-22 16:55:54]

On 2013/04/22 16:01:26, Eric Seidel (Google) wrote:

> Source/core/rendering/ExclusionPolygon.cpp:151: static inline FloatPolygon
> *computeShapeMarginBounds(const FloatPolygon& polygon, float margin, WindRule
> fillRule)
> * goes next to the type in WK style.

I've fixed this problem and will submit a separate patch for the smart pointer
changes.

Thanks for the review!

[commit-bot: I haz the power, 2013-04-22 17:35:22]

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

[commit-bot: I haz the power, 2013-04-22 17:39:55]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/hmuller@adobe.com/14220005/5001

[commit-bot: I haz the power, 2013-04-22 18:08:54]

Change committed as 148839

[esprehn, 2013-04-22 18:32:18]

This patch had the BUG= line first which means a useless git message, ex.
https://chromium.googlesource.com/chromium/blink.git

You should put them last instead.

[Hans Muller, 2013-04-23 15:23:34]

On 2013/04/22 16:01:26, Eric Seidel (Google) wrote:
> lgtm
> 
> The OwnPtr usage (since it clearly extends beyond this patch) can be done in a
> second pass.  But this code really should use smart pointers to avoid leaks.
:)

I've submitted a WebKit patch for this and will follow up with a Blink patch.
https://bugs.webkit.org/show_bug.cgi?id=114984