make the filter mode for GrTextureAccess an enum so we can plumb down

src/gpu/effects/GrSingleTextureEffect.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 "effects/GrSingleTextureEffect.h"
 
 GrSingleTextureEffect::GrSingleTextureEffect(GrTexture* texture,
                                              const SkMatrix& m,
                                              CoordsType coordsType)
     : fTextureAccess(texture)
     , fMatrix(m)
     , fCoordsType(coordsType) {
     this->addTextureAccess(&fTextureAccess);
 }
 
 GrSingleTextureEffect::GrSingleTextureEffect(GrTexture* texture,
                                              const SkMatrix& m,
-                                             bool bilerp,
+                                             GrTextureParams::FilterMode filterMode,
                                              CoordsType coordsType)
-    : fTextureAccess(texture, bilerp)
+    : fTextureAccess(texture, filterMode)
     , fMatrix(m)
     , fCoordsType(coordsType) {
     this->addTextureAccess(&fTextureAccess);
 }
 
 GrSingleTextureEffect::GrSingleTextureEffect(GrTexture* texture,
                                              const SkMatrix& m,
                                              const GrTextureParams& params,
                                              CoordsType coordsType)
     : fTextureAccess(texture, params)
     , fMatrix(m)
     , fCoordsType(coordsType) {
     this->addTextureAccess(&fTextureAccess);
 }
 
 GrSingleTextureEffect::~GrSingleTextureEffect() {
 }