skia: Add ANGLE with GL backend to nanobench/DM

dm/DMGpuSupport.h

 /*
  * Copyright 2014 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef DMGpuSupport_DEFINED
 #define DMGpuSupport_DEFINED
 
@@ skipping 47 matching lines @@
 struct GrContextOptions {};
 
 class GrContextFactory {
 public:
     GrContextFactory() {};
     explicit GrContextFactory(const GrContextOptions&) {}
 
     typedef int GLContextType;
 
     static const GLContextType kANGLE_GLContextType         = 0,
+                               kANGLE_GL_GLContextType      = 0,
                                kCommandBuffer_GLContextType = 0,
                                kDebug_GLContextType         = 0,
                                kMESA_GLContextType          = 0,
                                kNVPR_GLContextType          = 0,
                                kNative_GLContextType        = 0,
                                kNull_GLContextType          = 0;
     static const int kGLContextTypeCnt = 1;
     void destroyContexts() {}
 
     void abandonContexts() {}
@@ skipping 10 matching lines @@
                                        int,
                                        bool) {
     return nullptr;
 }
 
 }  // namespace DM
 
 #endif//SK_SUPPORT_GPU
 
 #endif//DMGpuSupport_DEFINED