Fix build with gperf ≥ 3.2

--- src/3rdparty/chromium/third_party/blink/renderer/build/scripts/gperf.py
+++ src/3rdparty/chromium/third_party/blink/renderer/build/scripts/gperf.py
@@ -38,8 +38,8 @@
         # -Wimplicit-fallthrough needs an explicit fallthrough statement,
         # so replace gperf's /*FALLTHROUGH*/ comment with the statement.
         # https://savannah.gnu.org/bugs/index.php?53029
-        gperf_output = gperf_output.replace('/*FALLTHROUGH*/',
-                                            '  FALLTHROUGH;')
+        #gperf_output = gperf_output.replace('/*FALLTHROUGH*/',
+        #                                    '  FALLTHROUGH;')
         # -Wpointer-to-int-cast warns about casting pointers to smaller ints
         # Replace {(int)(long)&(foo), bar} with
         # {static_cast<int>(reinterpret_cast<uintptr_t>(&(foo)), bar}