Revert "Revert "speed up A8 by creating a new entry-point in SkDraw that blits the path's coverage …

src/gpu/GrSWMaskHelper.cpp

 /*
  * Copyright 2012 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "GrSWMaskHelper.h"
 #include "GrDrawState.h"
 #include "GrDrawTargetCaps.h"
@@ skipping 55 matching lines @@
     } else {
         if (stroke.isFillStyle()) {
             paint.setStyle(SkPaint::kFill_Style);
         } else {
             paint.setStyle(SkPaint::kStroke_Style);
             paint.setStrokeJoin(stroke.getJoin());
             paint.setStrokeCap(stroke.getCap());
             paint.setStrokeWidth(stroke.getWidth());
         }
     }
+    paint.setAntiAlias(antiAlias);
 
-    SkXfermode* mode = SkXfermode::Create(op_to_mode(op));
-
-    paint.setXfermode(mode);
-    paint.setAntiAlias(antiAlias);
-    paint.setColor(SkColorSetARGB(alpha, alpha, alpha, alpha));
-
-    fDraw.drawPath(path, paint);
-
-    SkSafeUnref(mode);
+    if (SkRegion::kReplace_Op == op && 0xFF == alpha) {
+        SkASSERT(0xFF == paint.getAlpha());
+        fDraw.drawPathCoverage(path, paint);
+    } else {
+        paint.setXfermodeMode(op_to_mode(op));
+        paint.setColor(SkColorSetARGB(alpha, alpha, alpha, alpha));
+        fDraw.drawPath(path, paint);
+    }
 }
 
 bool GrSWMaskHelper::init(const SkIRect& resultBounds,
                           const SkMatrix* matrix) {
     if (NULL != matrix) {
         fMatrix = *matrix;
     } else {
         fMatrix.setIdentity();
     }
 
@@ skipping 108 matching lines @@
     maskMatrix.preConcat(drawState->getViewMatrix());
 
     drawState->addCoverageEffect(
                          GrSimpleTextureEffect::Create(texture,
                                                        maskMatrix,
                                                        GrTextureParams::kNone_FilterMode,
                                                        kPosition_GrCoordSet))->unref();
 
     target->drawSimpleRect(dstRect);
 }