https://bugs.webkit.org/show_bug.cgi?id=89767

Reviewed by Dirk Schulze.

Source/WebCore: 

The filter effect region for SVG feGaussian and feDropShadow filters
was incorrectly set, failing to account for the radius of the blur.
This patch fixes the problem and removes an unneccessary clip
operation when the filter result is blitted into the target. That clip
was clipping the shadow from webkit-shadow.

Tests: svg/filters/feDropShadow-subregion.svg
       svg/filters/feGaussianBlur-subregion.svg

* platform/graphics/filters/FEDropShadow.cpp:
(WebCore::FEDropShadow::determineAbsolutePaintRect): Moved the code
that clips the paint rect by the filter effect subregion to come after
the paint is modified by the filter radius.
* platform/graphics/filters/FEGaussianBlur.cpp:
(WebCore::FEGaussianBlur::determineAbsolutePaintRect):
Moved the code that clips the paint rect by the filter effect subregion to
come after the paint is modified by the filter radius.
* rendering/svg/RenderSVGResourceFilter.cpp:
(WebCore::RenderSVGResourceFilter::postApplyResource):
Removed a clip that is unnecessary and that was incorrectly clipping drop shadows.

LayoutTests: 

The filter effect region for SVG feGaussian and feDropShadow filters was incorrectly set,
failing to account for the radius of the blur. This patch fixes the problem and removes an
unneccessary clip operation when the filter result is blitted into the target. That clip
was clipping the shadow from webkit-shadow.

* platform/chromium/TestExpectations: Added temp entries for affected
tests. Will rebaseline later (not closing the bug in the meantime).
* svg/filters/feDropShadow-subregion-expected.png: Added.
* svg/filters/feDropShadow-subregion-expected.txt: Added.
* svg/filters/feDropShadow-subregion.svg: This verifies the subregion for feDropShadow.
* svg/filters/feGaussianBlur-subregion-expected.png: Added.
* svg/filters/feGaussianBlur-subregion-expected.txt: Added.
* svg/filters/feGaussianBlur-subregion.svg: This verifies the subregion for feGaussianBlur.


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@123210 268f45cc-cd09-0410-ab3c-d52691b4dbfc