Remove checks for _WIN32 in Windows-only files.

Change-Id: I753a6cce8896f9e7792ef6bacbd925d0fbe29534
Reviewed-on: https://pdfium-review.googlesource.com/c/pdfium/+/53755
Commit-Queue: Lei Zhang <thestig@chromium.org>
Reviewed-by: Tom Sepez <tsepez@chromium.org>
diff --git a/core/fxge/cfx_windowsrenderdevice.h b/core/fxge/cfx_windowsrenderdevice.h
index 454f448..ef4dc39 100644
--- a/core/fxge/cfx_windowsrenderdevice.h
+++ b/core/fxge/cfx_windowsrenderdevice.h
@@ -7,10 +7,7 @@
 #ifndef CORE_FXGE_CFX_WINDOWSRENDERDEVICE_H_
 #define CORE_FXGE_CFX_WINDOWSRENDERDEVICE_H_
 
-#ifdef _WIN32
-#ifndef _WINDOWS_
 #include <windows.h>
-#endif
 
 #include "core/fxge/cfx_renderdevice.h"
 
@@ -45,6 +42,4 @@
   static RenderDeviceDriverIface* CreateDriver(HDC hDC);
 };
 
-#endif  // _WIN32
-
 #endif  // CORE_FXGE_CFX_WINDOWSRENDERDEVICE_H_
diff --git a/core/fxge/win32/cfx_windowsdib.h b/core/fxge/win32/cfx_windowsdib.h
index edc1ed7..ef6127b 100644
--- a/core/fxge/win32/cfx_windowsdib.h
+++ b/core/fxge/win32/cfx_windowsdib.h
@@ -6,10 +6,8 @@
 
 #ifndef CORE_FXGE_WIN32_CFX_WINDOWSDIB_H_
 #define CORE_FXGE_WIN32_CFX_WINDOWSDIB_H_
-#ifdef _WIN32
-#ifndef _WINDOWS_
+
 #include <windows.h>
-#endif
 
 #include "core/fxcrt/bytestring.h"
 #include "core/fxge/dib/cfx_dibitmap.h"
@@ -51,6 +49,4 @@
   HBITMAP m_hOldBitmap;
 };
 
-#endif  // _WIN32
-
 #endif  // CORE_FXGE_WIN32_CFX_WINDOWSDIB_H_