Add config options to run different GPU APIs to dm and nanobench

dm/DMSrcSink.h

 /*
  * Copyright 2015 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef DMSrcSink_DEFINED
 #define DMSrcSink_DEFINED
 
@@ skipping 196 matching lines @@
 
     Error draw(const Src& src, SkBitmap*, SkWStream*, SkString*) const override;
     int enclave() const override { return kAnyThread_Enclave; }
     const char* fileExtension() const override { return ""; }
     SinkFlags flags() const override { return SinkFlags{ SinkFlags::kNull, SinkFlags::kDirect }; }
 };
 
 
 class GPUSink : public Sink {
 public:
-    GPUSink(GrContextFactory::GLContextType, GrGLStandard, int samples,
-            bool diText, bool threaded);
     GPUSink(GrContextFactory::GLContextType, GrContextFactory::GLContextOptions,
-            GrGLStandard, int samples, bool diText, bool threaded);
+            int samples, bool diText, bool threaded);
 
     Error draw(const Src&, SkBitmap*, SkWStream*, SkString*) const override;
     int enclave() const override;
     const char* fileExtension() const override { return "png"; }
     SinkFlags flags() const override { return SinkFlags{ SinkFlags::kGPU, SinkFlags::kDirect }; }
 private:
     GrContextFactory::GLContextType    fContextType;
     GrContextFactory::GLContextOptions fContextOptions;
-    GrGLStandard                       fGpuAPI;
     int                                fSampleCount;
     bool                               fUseDIText;
     bool                               fThreaded;
 };
 
 class PDFSink : public Sink {
 public:
     PDFSink(const char* rasterizer);
 
     Error draw(const Src&, SkBitmap*, SkWStream*, SkString*) const override;
@@ skipping 122 matching lines @@
 
 class ViaTwice : public Via {
 public:
     explicit ViaTwice(Sink* sink) : Via(sink) {}
     Error draw(const Src&, SkBitmap*, SkWStream*, SkString*) const override;
 };
 
 }  // namespace DM
 
 #endif//DMSrcSink_DEFINED