Replace uses of GR_API by SK_API.

gyp/gpu.gyp

 {
   'target_defaults': {
     'conditions': [
       ['skia_os != "win"', {
         'sources/': [ ['exclude', '_win.(h|cpp)$'],
         ],
       }],
       ['skia_os != "mac"', {
         'sources/': [ ['exclude', '_mac.(h|cpp|m|mm)$'],
         ],
@@ skipping 128 matching lines @@
       ],
       'sources': [
         '<@(skgpu_sources)',
         '<@(skgpu_native_gl_sources)',
         '<@(skgpu_angle_gl_sources)',
         '<@(skgpu_mesa_gl_sources)',
         '<@(skgpu_debug_gl_sources)',
         '<@(skgpu_null_gl_sources)',
         'gpu.gypi', # Makes the gypi appear in IDEs (but does not modify the build).
       ],
-      'defines': [
-        'GR_IMPLEMENTATION=1',
-      ],
       'conditions': [
         [ 'skia_nv_path_rendering', {
           'defines': [
             'GR_GL_USE_NV_PATH_RENDERING=1',
           ],
         }],
         [ 'skia_stroke_path_rendering', {
           'sources': [
             '../experimental/StrokePathRenderer/GrStrokePathRenderer.h',
             '../experimental/StrokePathRenderer/GrStrokePathRenderer.cpp',
@@ skipping 100 matching lines @@
       ],
     },
   ],
 }
 
 # Local Variables:
 # tab-width:2
 # indent-tabs-mode:nil
 # End:
 # vim: set expandtab tabstop=2 shiftwidth=2: