Move all text stuff to its own folder

src/gpu/text/GrTextContext.cpp

 /*
  * Copyright 2010 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "GrTextContext.h"
 #include "GrContext.h"
 #include "GrFontScaler.h"
@@ skipping 156 matching lines @@
     if (cache->getAuxProcData(GlyphCacheAuxProc, &auxData)) {
         scaler = (GrFontScaler*)auxData;
     }
     if (nullptr == scaler) {
         scaler = new GrFontScaler(cache);
         cache->setAuxProc(GlyphCacheAuxProc, scaler);
     }
 
     return scaler;
 }