Clobber to hopefully resolve a clang problem

BUG=chromium:500934
LOG=N
TBR=yangguo@chromium.org

Review URL: https://codereview.chromium.org/1486343003

Cr-Commit-Position: refs/heads/master@{#32493}

build/get_landmines.py

@@ -25,6 +25,7 @@ def main():
   print 'Remove build/android.gypi'
   print 'Cleanup after windows ninja switch attempt.'
   print 'Switching to pinned msvs toolchain.'
+  print 'Clobbering to hopefully resolve problem with mksnapshot'
   return 0