[build] Fix cfi build

NOTRY=true
NOTREECHECKS=true
TBR=vogelheim@chromium.org

Bug: chromium:726584
Change-Id: I7a20b8897e6db681acec76c135e4d17674e17729
Reviewed-on: https://chromium-review.googlesource.com/535517
Commit-Queue: Michael Achenbach <machenbach@chromium.org>
Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Reviewed-by: Daniel Vogelheim <vogelheim@chromium.org>
Cr-Commit-Position: refs/heads/master@{#45941}

gypfiles/standalone.gypi

@@ -1502,11 +1502,13 @@
               '-fsanitize=cfi-derived-cast',
               '-fsanitize=cfi-unrelated-cast',
               '-fsanitize-blacklist=<(cfi_blacklist)',
+              '-fwhole-program-vtables',
             ],
             'ldflags': [
               '-fsanitize=cfi-vcall',
               '-fsanitize=cfi-derived-cast',
               '-fsanitize=cfi-unrelated-cast',
+              '-fwhole-program-vtables',
             ],
           }],
         ],