GCC: avoid clash between getter and type FontPalette in blink::ComputedStyle

Add namespace to return type of blink::ComputedStyle::FontPalette to
avoid a clash between type declaration and getter.

Bug: 819294
Change-Id: Ib316232a45728a1e69d69a474245c514c98e2b29
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4573688
Reviewed-by: Rune Lillesveen <futhark@chromium.org>
Commit-Queue: José Dapena Paz <jdapena@igalia.com>
Cr-Commit-Position: refs/heads/main@{#1150618}
diff --git a/third_party/blink/renderer/core/style/computed_style.h b/third_party/blink/renderer/core/style/computed_style.h
index 07d900c..abe3832 100644
--- a/third_party/blink/renderer/core/style/computed_style.h
+++ b/third_party/blink/renderer/core/style/computed_style.h
@@ -881,7 +881,7 @@
   }
 
   // font-palette
-  FontPalette* FontPalette() const {
+  blink::FontPalette* FontPalette() const {
     return GetFontDescription().GetFontPalette();
   }