https://bugs.webkit.org/show_bug.cgi?id=106221

Reviewed by Dean Jackson.

Source/WebCore:

Since the cached filter results are not invalidated for different repaint rects, we need
to render the content of the whole filter region upfront (otherwise elements not visible
during the initial paint due to scrolling/window size/etc. are never redrawn).

Tests: svg/filters/filter-hidden-content-expected.svg
       svg/filters/filter-hidden-content.svg

* rendering/svg/RenderSVGResourceFilter.cpp:
(WebCore::RenderSVGResourceFilter::applyResource):
(WebCore::RenderSVGResourceFilter::drawingRegion):
(WebCore):
* rendering/svg/RenderSVGResourceFilter.h:
(FilterData):
(RenderSVGResourceFilter):
Track the filter drawing region in FilterData.

* rendering/svg/SVGRenderingContext.cpp:
(WebCore::SVGRenderingContext::~SVGRenderingContext):
(WebCore::SVGRenderingContext::prepareToRenderSVGContent):
* rendering/svg/SVGRenderingContext.h:
Update paintInfo.rect to cover the whole drawing region while rendering filter content, and
restore it when done.

LayoutTests:

* svg/filters/filter-hidden-content-expected.svg: Added.
* svg/filters/filter-hidden-content.svg: Added.


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@142955 268f45cc-cd09-0410-ab3c-d52691b4dbfc