BUILD.gn - put cfx_windowsrenderdevice.h in win-specific section.

It just looks wrong otherwise.

Change-Id: Id4f45d9111a76a78ec35c8234465d2cdf93299bc
Reviewed-on: https://pdfium-review.googlesource.com/41090
Commit-Queue: Ryan Harrison <rharrison@chromium.org>
Reviewed-by: Ryan Harrison <rharrison@chromium.org>
diff --git a/BUILD.gn b/BUILD.gn
index 73b4382..b3a56f7 100644
--- a/BUILD.gn
+++ b/BUILD.gn
@@ -1041,7 +1041,6 @@
     "core/fxge/cfx_substfont.h",
     "core/fxge/cfx_unicodeencoding.cpp",
     "core/fxge/cfx_unicodeencoding.h",
-    "core/fxge/cfx_windowsrenderdevice.h",
     "core/fxge/cttfontdesc.cpp",
     "core/fxge/cttfontdesc.h",
     "core/fxge/dib/cfx_bitmapcomposer.cpp",
@@ -1137,6 +1136,7 @@
 
   if (is_win) {
     sources += [
+      "core/fxge/cfx_windowsrenderdevice.h",
       "core/fxge/win32/cfx_psrenderer.cpp",
       "core/fxge/win32/cfx_psrenderer.h",
       "core/fxge/win32/cpsoutput.cpp",