commit 7f72efd257ec544cdf9cd5ce000f8af2a030963a
author fs@opera.com <fs@opera.com> Tue Sep 22 21:05:18 2015
committer fs@opera.com <fs@opera.com> Tue Sep 22 21:05:18 2015
tree 2e9f33fa54b497e34550d240330731d26616d88e
parent 13a86eb5e7e1590087cdc8c89a684db1fee007a9

Update handling of negative std.dev for feGaussianblur/feDropShadow

Spec[1] states:

 "A negative value or a value of zero disables the effect of the given
  filter primitive (i.e., the result is the filter input image)."

Update SVGFEGaussianBlurElement and SVGFEDropShadowElement to reflect
this, and update the references for the corresponding tests.

Drop accessors on FEDropShadow because they are unused.

[1] https://drafts.fxtf.org/filters/#element-attrdef-fegaussianblur-stddeviation

BUG=533457

Review URL: https://codereview.chromium.org/1350903009

git-svn-id: svn://svn.chromium.org/blink/trunk@202643 bbb929c8-8fbe-4397-9dbb-9b2b20218538