Remove SVGGraphicsElement::getStrokeBBox()

The world was not ready for getStrokeBBox(). This API is (correctly)
being removed from SVG2[1] and replaced with a dictionary
argument on the getBBox() function.

This patch reverts r160684[2] which implemented getStrokeBBox() too soon.

[1] http://lists.w3.org/Archives/Public/www-svg/2013Jan/0057.html
[2] http://src.chromium.org/viewvc/blink?view=rev&rev=160684

BUG=280423

Review URL: https://codereview.chromium.org/153553003

git-svn-id: svn://svn.chromium.org/blink/trunk@166425 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Remove all usage of -webkit-*gradient inside blink

The prefixed functions have been deprecated in 2011 and should
be use counted with the goal of removing them.

This patch just rewrites existing rules on top of the modern syntax:

-webkit-gradient(linear, top left, bottom left, from(white), to(black))

is equivalent to

linear-gradient(to bottom, white, black)

Review URL: https://codereview.chromium.org/152493003

git-svn-id: svn://svn.chromium.org/blink/trunk@166426 bbb929c8-8fbe-4397-9dbb-9b2b20218538