remove U16 support, just support F16

src/core/SkCoreBlitters.h

 /*
  * Copyright 2006 The Android Open Source Project
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef SkCoreBlitters_DEFINED
 #define SkCoreBlitters_DEFINED
 
@@ skipping 167 matching lines @@
     SkBlitRow::Proc32   fProc32;
     SkBlitRow::Proc32   fProc32Blend;
     bool                fShadeDirectlyIntoDevice;
 
     // illegal
     SkARGB32_Shader_Blitter& operator=(const SkARGB32_Shader_Blitter&);
 
     typedef SkShaderBlitter INHERITED;
 };
 
-SkBlitter* SkBlitter_ARGB32_Create(const SkPixmap& device, const SkPaint& paint,
-                                   SkShader::Context* shaderContext,
-                                   SkTBlitterAllocator* allocator);
+SkBlitter* SkBlitter_ARGB32_Create(const SkPixmap& device, const SkPaint&, SkShader::Context*,
+                                   SkTBlitterAllocator*);
 
-SkBlitter* SkBlitter_ARGB64_Create(const SkPixmap& device, const SkPaint& paint,
-                                   SkShader::Context* shaderContext,
-                                   SkTBlitterAllocator* allocator);
+SkBlitter* SkBlitter_F16_Create(const SkPixmap& device, const SkPaint&, SkShader::Context*,
+                                SkTBlitterAllocator*);
 
 ///////////////////////////////////////////////////////////////////////////////
 
 /*  These return the correct subclass of blitter for their device config.
 
     Currently, they make the following assumptions about the state of the
     paint:
 
     1. If there is an xfermode, there will also be a shader
     2. If there is a colorfilter, there will be a shader that itself handles
        calling the filter, so the blitter can always ignore the colorfilter obj
 
     These pre-conditions must be handled by the caller, in our case
     SkBlitter::Choose(...)
  */
 
 SkBlitter* SkBlitter_ChooseD565(const SkPixmap& device, const SkPaint& paint,
                                 SkShader::Context* shaderContext,
                                 SkTBlitterAllocator* allocator);
 
 #endif