Move all text stuff to its own folder

src/gpu/text/GrDistanceFieldAdjustTable.cpp

 /*
  * Copyright 2015 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "GrDistanceFieldAdjustTable.h"
 
 #include "SkScalerContext.h"
@@ skipping 73 matching lines @@
                 // compute distance which gives us that t value
                 const float kDistanceFieldAAFactor = 0.65f; // should match SK_DistanceFieldAAFactor
                 float d = 2.0f*kDistanceFieldAAFactor*t - kDistanceFieldAAFactor;
 
                 fTable[row] = d;
                 break;
             }
         }
     }
 }