Add minimum size for using distance fields.

src/gpu/effects/GrDistanceFieldTextureEffect.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 "GrDistanceFieldTextureEffect.h"
 #include "GrFontAtlasSizes.h"
 #include "GrInvariantOutput.h"
 #include "GrTexture.h"
 #include "SkDistanceFieldGen.h"
 #include "gl/GrGLProcessor.h"
 #include "gl/GrGLSL.h"
 #include "gl/GrGLTexture.h"
 #include "gl/GrGLGeometryProcessor.h"
 #include "gl/builders/GrGLProgramBuilder.h"
 
 // Assuming a radius of the diagonal of the fragment, hence a factor of sqrt(2)/2
-#define SK_DistanceFieldAAFactor     "0.7071"
+#define SK_DistanceFieldAAFactor     "0.65"
 
 struct DistanceFieldBatchTracker {
     GrGPInput fInputColorType;
     GrColor fColor;
     bool fUsesLocalCoords;
 };
 
 class GrGLDistanceFieldTextureEffect : public GrGLGeometryProcessor {
 public:
     GrGLDistanceFieldTextureEffect(const GrGeometryProcessor&,
@@ skipping 827 matching lines @@
     uint32_t flags = kUseLCD_DistanceFieldEffectFlag;
     flags |= random->nextBool() ? kUniformScale_DistanceFieldEffectMask : 0;
     flags |= random->nextBool() ? kBGR_DistanceFieldEffectFlag : 0;
     return GrDistanceFieldLCDTextureEffect::Create(GrRandomColor(random),
                                                    GrProcessorUnitTest::TestMatrix(random),
                                                    textures[texIdx], params,
                                                    textures[texIdx2], params2,
                                                    textColor,
                                                    flags);
 }