[skia] Implement reference (url) filters on composited layers.
https://bugs.webkit.org/show_bug.cgi?id=100142

Reviewed by James Robinson.

Source/Platform:

* chromium/public/WebLayer.h:
Expose Layer::setFilter() to the WebKit API.

Source/WebCore:

Covered by css3/filters/effect-reference-hw.html

* WebCore.gyp/WebCore.gyp:
* WebCore.gypi:
Add new files.
* WebCore.xcodeproj/project.pbxproj:
Mark FilterEffect.h as "private".
* platform/graphics/chromium/GraphicsLayerChromium.cpp:
(WebCore::GraphicsLayerChromium::setFilters):
Use the new SkImageFilter builder and setLayer() infrastructure, but
only if there's a reference filter in the chain.
* platform/graphics/filters/FEBlend.h:
* platform/graphics/filters/FEColorMatrix.h:
* platform/graphics/filters/FEGaussianBlur.h:
* platform/graphics/filters/FELighting.h:
* platform/graphics/filters/FEMorphology.h:
* platform/graphics/filters/FilterEffect.h:
(WebCore::FilterEffect::createImageFilter):
Add createImageFilter() factory function for building SkImageFilters.
* platform/graphics/filters/FilterOperation.h:
(WebCore::FilterOperation::ReferenceFilterOperation::filterEffect):
(WebCore::FilterOperation::ReferenceFilterOperation::setFilterEffect):
Add a FilterEffect member to ReferenceFilterOperation, and accessors
for it.
* platform/graphics/filters/skia/FEBlendSkia.cpp:
(WebCore::FEBlend::createImageFilter):
Implement SkImageFilter building for FEBlend filter.
* platform/graphics/filters/skia/FEColorMatrixSkia.cpp:
(WebCore::createColorFilter):
(WebCore::FEColorMatrix::platformApplySkia):
Refactor creation of SkColorFilter from an FEColorMatrix filter.
(WebCore::FEColorMatrix::createImageFilter):
Implement SkImageFilter building for FEColorMatrix filter.
* platform/graphics/filters/skia/FEGaussianBlurSkia.cpp:
(WebCore::FEGaussianBlur::createImageFilter):
Implement SkImageFilter building for FEGaussianBlur filter.
* platform/graphics/filters/skia/FELightingSkia.cpp:
(WebCore::FELighting::createImageFilter):
Implement SkImageFilter building for FELighting filters.
* platform/graphics/filters/skia/FEMorphologySkia.cpp:
(WebCore::FEMorphology::createImageFilter):
Implement SkImageFilter building for FEMorphology filter.
* platform/graphics/filters/skia/SkiaImageFilterBuilder.cpp: Added.
(WebCore::SkiaImageFilterBuilder::SkiaImageFilterBuilder):
(WebCore::SkiaImageFilterBuilder::build):
* platform/graphics/filters/skia/SkiaImageFilterBuilder.h:
Implement new helper class for building an SkImageFilter DAG from
a FilterEffect DAG.  Can also build from FilterOperations list.
* rendering/FilterEffectRenderer.cpp:
(WebCore::FilterEffectRenderer::build):
When building FilterEffects from a reference filter, also store the
generated DAG on the ReferenceFilterOperation itself.
* rendering/RenderLayer.cpp:
(WebCore::RenderLayer::updateOrRemoveFilterEffect):
Even when in composited mode, if there's a reference filter in the
chain, build the FilterEffect DAG from it.

git-svn-id: https://svn.webkit.org/repository/webkit/trunk/Source/Platform/chromium/public@133608 268f45cc-cd09-0410-ab3c-d52691b4dbfc