clang/win: Disable -Wunused-local-typedef for now.

BUG=411648,82385
TBR=hans@chromium.org

Review URL: https://codereview.chromium.org/550713002

Cr-Commit-Position: refs/heads/master@{#293635}

build/common.gypi

@@ -5501,6 +5501,7 @@
                   '-Wno-unused-private-field',
                   '-Wno-unused-value',
                   '-Wno-unused-variable',
+                  '-Wno-unused-local-typedef',  # http://crbug.com/411648
                 ],
               },
             }],