Fix duplicate header file entry

Change crrev.com/c/50077 introduced a duplicate BUILD.gn entry for
scoped_font_transform.h. This then causes a VS warning when loading
a solution file created by gn. This removes the duplicate.

Bug: chromium:1048779
Change-Id: Iec3d760da9295aef5ca353f46f2c27b85edf6131
Reviewed-on: https://pdfium-review.googlesource.com/c/pdfium/+/66070
Reviewed-by: Lei Zhang <thestig@chromium.org>
Auto-Submit: Bruce Dawson <brucedawson@chromium.org>
Commit-Queue: Bruce Dawson <brucedawson@chromium.org>

core/fxge/BUILD.gn

diff --git a/core/fxge/BUILD.gn b/core/fxge/BUILD.gn
index 88de3d9..2b90c21 100644
--- a/core/fxge/BUILD.gn
+++ b/core/fxge/BUILD.gn
@@ -103,7 +103,6 @@
     "renderdevicedriver_iface.h",
     "scoped_font_transform.cpp",
     "scoped_font_transform.h",
-    "scoped_font_transform.h",
     "systemfontinfo_iface.h",
     "text_char_pos.cpp",
     "text_char_pos.h",