Add XferProcessor factory in GrPaint and GrDrawState.

src/gpu/GrDistanceFieldTextContext.cpp

 /*
  * Copyright 2013 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "GrDistanceFieldTextContext.h"
 #include "GrAtlas.h"
 #include "GrBitmapTextContext.h"
@@ skipping 642 matching lines @@
             filteredColor = fSkPaint.getColor();
         }
         this->setupCoverageEffect(filteredColor);
 
         // Effects could be stored with one of the cache objects (atlas?)
         drawState.setGeometryProcessor(fCachedGeometryProcessor.get());
 
         // Set draw state
         if (fUseLCDText) {
             GrColor colorNoPreMul = skcolor_to_grcolor_nopremultiply(filteredColor);
-            if (kOne_GrBlendCoeff != fPaint.getSrcBlendCoeff() ||
-                kISA_GrBlendCoeff != fPaint.getDstBlendCoeff() ||
-                fPaint.numColorStages()) {
+
+            // TODO: move supportsRGBCoverage check to setupCoverageEffect and only add LCD
+            // processor if the xp can support it. For now we will simply assume that if
+            // fUseLCDText is true, then we have a known color output.
+            if (!drawState.getXPFactory()->supportsRGBCoverage(0, kRGBA_GrColorComponentFlags)) {
                 SkDebugf("LCD Text will not draw correctly.\n");
             }
             SkASSERT(!drawState.hasColorVertexAttribute());
             // We don't use the GrPaint's color in this case because it's been premultiplied by
             // alpha. Instead we feed in a non-premultiplied color, and multiply its alpha by
             // the mask texture color. The end result is that we get
             //            mask*paintAlpha*paintColor + (1-mask*paintAlpha)*dstColor
             int a = SkColorGetA(fSkPaint.getColor());
             // paintAlpha
             drawState.setColor(SkColorSetARGB(a, a, a, a));
@@ skipping 26 matching lines @@
     }
 }
 
 inline void GrDistanceFieldTextContext::finish() {
     this->flush();
     fTotalVertexCount = 0;
 
     GrTextContext::finish();
 }