Silence TSAN warnings about is_lcd_supported for now.

BUG=skia:1792

NOTRY=true
R=bungeman@google.com, mtklein@google.com

Author: mtklein@chromium.org

Review URL: https://codereview.chromium.org/328663006
diff --git a/tools/tsan.supp b/tools/tsan.supp
index 0b07f62..31074cc 100644
--- a/tools/tsan.supp
+++ b/tools/tsan.supp
@@ -14,10 +14,9 @@
 
 # Threadsafe, should be ported to SkLazyPtr.
 race:SkFontHost_FreeType
+race:is_lcd_supported
 
 # Not threadsafe, should be fixed.
 race:RefFCI
 race:SkString
-
-# Not threadsafe, should be deleted.
 race:SkPDF