Fix -Wswitch warning in cfpf_skiafontmgr.cpp

Android was compiling pdfium's fxge without -Wno-switch, which found a
warning in android/cfpf_skiafontmgr.cpp.  -Wno-switch was added for a
windows-only file in crrev.com/1301473003, fix the new -Wswitch warning
and re-enable -Wswitch for non-windows builds.

Change-Id: I455e9e7324bf9e8ad39a43898354d86fb77c8c24
Reviewed-on: https://pdfium-review.googlesource.com/c/pdfium/+/106070
Commit-Queue: Lei Zhang <thestig@chromium.org>
Reviewed-by: Lei Zhang <thestig@chromium.org>
diff --git a/core/fxge/BUILD.gn b/core/fxge/BUILD.gn
index d05386f..944ee3c 100644
--- a/core/fxge/BUILD.gn
+++ b/core/fxge/BUILD.gn
@@ -6,7 +6,7 @@
 import("../../pdfium.gni")
 import("../../testing/test.gni")
 
-config("fxge_warnings") {
+config("fxge_windows_warnings") {
   visibility = [ ":*" ]
   if (is_clang) {
     cflags = [
@@ -119,7 +119,7 @@
   ]
 
   configs += [
-    ":fxge_warnings",
+    ":fxge_windows_warnings",
     "../../:pdfium_strict_config",
     "../../:pdfium_noshorten_config",
   ]
diff --git a/core/fxge/android/cfpf_skiafontmgr.cpp b/core/fxge/android/cfpf_skiafontmgr.cpp
index aa384fb..036f812 100644
--- a/core/fxge/android/cfpf_skiafontmgr.cpp
+++ b/core/fxge/android/cfpf_skiafontmgr.cpp
@@ -119,8 +119,9 @@
       return FPF_SKIACHARSET_Thai;
     case FX_Charset::kMSWin_EasternEuropean:
       return FPF_SKIACHARSET_EeasternEuropean;
+    default:
+      return FPF_SKIACHARSET_Default;
   }
-  return FPF_SKIACHARSET_Default;
 }
 
 uint32_t FPF_SKIANormalizeFontName(ByteStringView bsFamily) {