make internaldrawBmpText part of GrTextUtils

src/gpu/GrTextContext.h

 /*
  * Copyright 2010 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef GrTextContext_DEFINED
 #define GrTextContext_DEFINED
 
@@ skipping 51 matching lines @@
                                const GrPaint&, const SkPaint&,
                                const SkMatrix& viewMatrix,
                                const char text[], size_t byteLength,
                                const SkScalar pos[], int scalarsPerPosition,
                                const SkPoint& offset, const SkIRect& clipBounds) = 0;
 
     static GrFontScaler* GetGrFontScaler(SkGlyphCache* cache);
     static uint32_t FilterTextFlags(const SkSurfaceProps& surfaceProps, const SkPaint& paint);
 
     friend class GrAtlasTextBatch;
-    friend class GrAtlasTextBlob; // for drawTextAsPath
+    friend class GrAtlasTextBlob; // for FilterTextFlags
+    friend class GrTextUtils; // for some static functions
 };
 
 #endif