Fix typo in simple-polygon.js LayoutTest helper

Fix typo in simple-polygon.js LayoutTest helper

The lineHeight parameter to generatePolygonContentString() is mistyped as
'lineheight'.

It looks like this bug has always been present. It doesn't currently create a
problem because in all cases where this function is called, a global variable
named 'lineHeight' exists with the correct value.

See https://src.chromium.org/viewvc/blink?view=revision&revision=130687

Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=161112

[Hans Muller, 2013-10-31 04:13:55]

On 2013/10/31 02:39:59, Steve Block wrote:

This change LGTM and I have to admit that I'm a little embarrassed to be the
source of the problem.

What caused you to find the mistake?

[Steve Block, 2013-10-31 23:14:35]

We've been working on animating line-height in Web Animations and I happened to
do this ...

$ git grep lineheight LayoutTests/
LayoutTests/fast/shapes/resources/simple-polygon.js:function
generatePolygonContentString(polygon, lineheight) {

Getting only 1 hit seemed very odd!

[commit-bot: I haz the power, 2013-10-31 23:14:55]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/steveblock@chromium.org/53583005/1

[commit-bot: I haz the power, 2013-11-01 00:12:41]

Change committed as 161112