Implement color filter as GrGLEffect

src/gpu/GrDrawState.cpp

Index: src/gpu/GrDrawState.cpp
diff --git a/src/gpu/GrDrawState.cpp b/src/gpu/GrDrawState.cpp
index d1d6c5813ef50d8a466de2faefe8c08945277058..1743604a19a505a498309f229aa90f390f9353b8 100644
--- a/src/gpu/GrDrawState.cpp
+++ b/src/gpu/GrDrawState.cpp
@@ -59,7 +59,6 @@ void GrDrawState::setFromPaint(const GrPaint& paint, const SkMatrix& vm, GrRende
     this->setState(GrDrawState::kHWAntialias_StateBit, paint.isAntiAlias());
 
     this->setBlendFunc(paint.getSrcBlendCoeff(), paint.getDstBlendCoeff());
-    this->setColorFilter(paint.getColorFilterColor(), paint.getColorFilterMode());
     this->setCoverage(paint.getCoverage());
 }
 
@@ -219,13 +218,6 @@ bool GrDrawState::srcAlphaWillBeOne() const {
         (*effect)->getConstantColorComponents(&color, &validComponentFlags);
     }
 
-    // Check if the color filter could introduce an alpha.
-    // We could skip the above work when this is true, but it is rare and the right fix is to make
-    // the color filter a GrEffect and implement getConstantColorComponents() for it.
-    if (SkXfermode::kDst_Mode != this->getColorFilterMode()) {
-        validComponentFlags = 0;
-    }
-
     // Check whether coverage is treated as color. If so we run through the coverage computation.
     if (this->isCoverageDrawing()) {
         GrColor coverageColor = this->getCoverage();