Get correct text metrics for distance fields, and fix dropouts due to thin features.

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 "GrDrawTarget.h"
@@ skipping 290 matching lines @@
     fCurrVertex = 0;
 
     fVertices = NULL;
     fMaxVertices = 0;
 
     fTextRatio = fSkPaint.getTextSize()/kBaseDFFontSize;
 
     fSkPaint.setTextSize(SkIntToScalar(kBaseDFFontSize));
     fSkPaint.setLCDRenderText(false);
     fSkPaint.setAutohinted(false);
-    fSkPaint.setSubpixelText(false);
+    fSkPaint.setSubpixelText(true);
+    fSkPaint.setLinearText(true);

[reed1, 2014/03/14 18:32:50]

This field is of questionable meaning :) Did you need to turn this on after
testing, or just speculative? I would have guessed that only subpixel was
needed.

[jvanverth1, 2014/03/14 18:46:02]

Purely speculative. It's gone.

 }
 
 inline void GrDistanceFieldTextContext::finish() {
     flushGlyphs();
 
     GrTextContext::finish();
 }
 
 void GrDistanceFieldTextContext::drawText(const GrPaint& paint, const SkPaint& skPaint,
                                           const char text[], size_t byteLength,
@@ skipping 127 matching lines @@
                                       SkScalarToFixed(y) - (glyph.fAdvanceY >> alignShift)
                                         + SK_FixedHalf, //d1g.fHalfSampleY,
                                       fontScaler);
             }
             pos += scalarsPerPosition;
         }
     }
 
     this->finish();
 }