gpu: Add calling convention for win32

skia/BUILD.gn

 # Copyright (c) 2013 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 import("//build/config/features.gni")
 import("//build/config/ui.gni")
 import("//testing/test.gni")
 if (current_cpu == "arm") {
   import("//build/config/arm.gni")
 }
@@ skipping 151 matching lines @@
   if (is_android) {
     defines += [
       "SK_BUILD_FOR_ANDROID",
       "USE_CHROMIUM_SKIA",
     ]
   }
 
   if (is_mac) {
     defines += [ "SK_BUILD_FOR_MAC" ]
   }
+
+  if (is_win) {
+    defines += [ "GR_GL_FUNCTION_TYPE=__stdcall" ]
+  }
 }
 
 # Internal-facing config for Skia library code.
 config("skia_library_config") {
   # These include directories are only included for Skia code and are not
   # exported to dependents. It's not clear if this is on purpose, but this
   # matches the GYP build.
   include_dirs = [
     "//third_party/skia/include/private",
     "//third_party/skia/src/core",
@@ skipping 459 matching lines @@
       "tools/filter_fuzz_stub/filter_fuzz_stub.cc",
     ]
 
     deps = [
       ":skia",
       "//base",
       "//base/test:test_support",
     ]
   }
 }