Hook in rough distance field support for fonts

src/gpu/effects/GrDistanceFieldTextureEffect.h

 /*
  * Copyright 2013 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
-#ifndef GrCustomCoordsTextureEffect_DEFINED
-#define GrCustomCoordsTextureEffect_DEFINED
+#ifndef GrDistanceFieldTextureEffect_DEFINED
+#define GrDistanceFieldTextureEffect_DEFINED
 
 #include "GrEffect.h"
 #include "GrVertexEffect.h"
 
-class GrGLCustomCoordsTextureEffect;
+class GrGLDistanceFieldTextureEffect;
 
 /**
- * The output color of this effect is a modulation of the input color and a sample from a texture.
+ * The output color of this effect is a modulation of the input color and a sample from a 
+ * distance field texture (using a smoothed step function near 0.5).
  * It allows explicit specification of the filtering and wrap modes (GrTextureParams). The input
  * coords are a custom attribute.
  */
-class GrCustomCoordsTextureEffect : public GrVertexEffect {
+class GrDistanceFieldTextureEffect : public GrVertexEffect {
 public:
     static GrEffectRef* Create(GrTexture* tex, const GrTextureParams& p) {
-        AutoEffectUnref effect(SkNEW_ARGS(GrCustomCoordsTextureEffect, (tex, p)));
+        AutoEffectUnref effect(SkNEW_ARGS(GrDistanceFieldTextureEffect, (tex, p)));
         return CreateEffectRef(effect);
     }
 
-    virtual ~GrCustomCoordsTextureEffect() {}
+    virtual ~GrDistanceFieldTextureEffect() {}
 
     static const char* Name() { return "Texture"; }
 
     virtual void getConstantColorComponents(GrColor* color, uint32_t* validFlags) const SK_OVERRIDE;
 
-    typedef GrGLCustomCoordsTextureEffect GLEffect;
+    typedef GrGLDistanceFieldTextureEffect GLEffect;
 
     virtual const GrBackendEffectFactory& getFactory() const SK_OVERRIDE;
 
 private:
-    GrCustomCoordsTextureEffect(GrTexture* texture, const GrTextureParams& params);
+    GrDistanceFieldTextureEffect(GrTexture* texture, const GrTextureParams& params);
 
     virtual bool onIsEqual(const GrEffect& other) const SK_OVERRIDE;
 
     GrTextureAccess fTextureAccess;
 
     GR_DECLARE_EFFECT_TEST;
 
     typedef GrVertexEffect INHERITED;
 };
 
 #endif