Fixed Shadow blur for transparent objects

Source/platform/graphics/GraphicsContextState.cpp

Index: Source/platform/graphics/GraphicsContextState.cpp
diff --git a/Source/platform/graphics/GraphicsContextState.cpp b/Source/platform/graphics/GraphicsContextState.cpp
index 657d0df5fb03942dbf1f6e356445b25f861889f6..1424bf473c4006f6ca58b8f2a11e92685da6057c 100644
--- a/Source/platform/graphics/GraphicsContextState.cpp
+++ b/Source/platform/graphics/GraphicsContextState.cpp
@@ -47,6 +47,7 @@ GraphicsContextState::GraphicsContextState(const GraphicsContextState& other)
     , m_fillGradient(other.m_fillGradient)
     , m_fillPattern(other.m_fillPattern)
     , m_looper(other.m_looper)
+    , m_imageFilter(other.m_imageFilter)
     , m_textDrawingMode(other.m_textDrawingMode)
     , m_alpha(other.m_alpha)
     , m_colorFilter(other.m_colorFilter)
@@ -204,6 +205,21 @@ void GraphicsContextState::clearDrawLooper()
     m_fillPaint.setLooper(0);
 }
 
+// Shadow. (This will need tweaking if we use image filters for other things.)

[Stephen White, 2014/10/23 01:45:47]

Pls remove this comment.

[sugoi1, 2014/10/23 17:43:17]

Done.

+void GraphicsContextState::setImageFilter(PassRefPtr<SkImageFilter> imageFilter)
+{
+    m_imageFilter = imageFilter;
+    m_strokePaint.setImageFilter(m_imageFilter.get());

[Stephen White, 2014/10/23 01:45:47]

I don't think this is correct. If we set an image filter in the paint, it will
be active at the same time as the draw looper. I think we should use it only in
the setup for drawRectToRect.

This also may be why you're getting more layout test failures than expected.

[sugoi1, 2014/10/23 17:43:17]

Done.

+    m_fillPaint.setImageFilter(m_imageFilter.get());
+}
+
+void GraphicsContextState::clearImageFilter()
+{
+    m_imageFilter.clear();
+    m_strokePaint.setImageFilter(0);

[Stephen White, 2014/10/23 01:45:47]

Same here.

[sugoi1, 2014/10/23 17:43:17]

Done.

+    m_fillPaint.setImageFilter(0);
+}
+
 void GraphicsContextState::setAlphaAsFloat(float alpha)
 {
     if (alpha < 0) {