Use D3D11 backend for ANGLE when available.

gyp/gpu.gypi

 # Include this gypi to include all 'gpu' files
 # The parent gyp/gypi file must define
 #       'skia_src_path'     e.g. skia/trunk/src
 #       'skia_include_path' e.g. skia/trunk/include
 #
 # The skia build defines these in common_variables.gypi
 #
 {
   'variables': {
     'skgpu_sources': [
@@ skipping 334 matching lines @@
       '<(skia_src_path)/gpu/gl/mesa/GrGLCreateMesaInterface.cpp',
 
       # Sk files
       '<(skia_src_path)/gpu/gl/mesa/SkMesaGLContext.cpp',
       '<(skia_src_path)/gpu/gl/mesa/SkMesaGLContext.h',
     ],
     'skgpu_angle_gl_sources': [
       '<(skia_src_path)/gpu/gl/angle/GrGLCreateANGLEInterface.cpp',
 
       # Sk files
+      '<(skia_include_path)/gpu/gl/angle/SkANGLEGLContext.h',
       '<(skia_src_path)/gpu/gl/angle/SkANGLEGLContext.cpp',
-      '<(skia_src_path)/gpu/gl/angle/SkANGLEGLContext.h',
     ],
     'skgpu_debug_gl_sources': [
       '<(skia_src_path)/gpu/gl/debug/GrGLCreateDebugInterface.cpp',
       '<(skia_src_path)/gpu/gl/debug/GrFakeRefObj.h',
       '<(skia_src_path)/gpu/gl/debug/GrBufferObj.h',
       '<(skia_src_path)/gpu/gl/debug/GrBufferObj.cpp',
       '<(skia_src_path)/gpu/gl/debug/GrFBBindableObj.h',
       '<(skia_src_path)/gpu/gl/debug/GrRenderBufferObj.h',
       '<(skia_src_path)/gpu/gl/debug/GrTextureObj.h',
       '<(skia_src_path)/gpu/gl/debug/GrTextureObj.cpp',
@@ skipping 13 matching lines @@
       '<(skia_src_path)/gpu/gl/debug/SkDebugGLContext.cpp',
       '<(skia_src_path)/gpu/gl/debug/SkDebugGLContext.h',
     ],
     'skgpu_null_gl_sources': [
       '<(skia_src_path)/gpu/gl/GrGLCreateNullInterface.cpp',
       '<(skia_src_path)/gpu/gl/SkNullGLContext.cpp',
       '<(skia_include_path)/gpu/gl/SkNullGLContext.h',
     ],
   },
 }