Avoid including string_view_template.h directly.

Prefer fx_string.h, since the use of the template is essentially
an implementation detail that can be hidden behind it.

Change-Id: I124146605d48243e2379a94f611386c346be6566
Reviewed-on: https://pdfium-review.googlesource.com/c/pdfium/+/65670
Reviewed-by: Lei Zhang <thestig@chromium.org>
Commit-Queue: Tom Sepez <tsepez@chromium.org>
diff --git a/core/fxcrt/css/cfx_cssdata.h b/core/fxcrt/css/cfx_cssdata.h
index 8fa2488..d5b6151 100644
--- a/core/fxcrt/css/cfx_cssdata.h
+++ b/core/fxcrt/css/cfx_cssdata.h
@@ -10,7 +10,7 @@
 #include "core/fxcrt/css/cfx_css.h"
 #include "core/fxcrt/css/cfx_cssnumbervalue.h"
 #include "core/fxcrt/css/cfx_cssvalue.h"
-#include "core/fxcrt/string_view_template.h"
+#include "core/fxcrt/fx_string.h"
 #include "core/fxge/fx_dib.h"
 
 class CFX_CSSData {