Use lowercase windows.h in includes to fix Windows cross compilation using mingw.

src/gpu/gl/win/GrGLCreateNativeInterface_win.cpp

 
 /*
  * Copyright 2011 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 
 #include "gl/GrGLExtensions.h"
 #include "gl/GrGLInterface.h"
 #include "gl/GrGLUtil.h"
 #define WIN32_LEAN_AND_MEAN
-#include <Windows.h>
+#include <windows.h>
 
 /*
  * Windows makes the GL funcs all be __stdcall instead of __cdecl :(
  * This implementation will only work if GR_GL_FUNCTION_TYPE is __stdcall.
  * Otherwise, a springboard would be needed that hides the calling convention.
  */
 
 #define SET_PROC(F) interface->f ## F = (GrGL ## F ## Proc) GetProcAddress(alu.get(), "gl" #F);
 #define WGL_SET_PROC(F) interface->f ## F = (GrGL ## F ## Proc) wglGetProcAddress("gl" #F);
 #define WGL_SET_PROC_SUFFIX(F, S) interface->f ## F = \
@@ skipping 286 matching lines @@
             WGL_SET_PROC_SUFFIX(PointAlongPath, NV);
         }
 
         interface->fBindingsExported = kDesktop_GrGLBinding;
 
         return interface;
     } else {
         return NULL;
     }
 }