
Guard static initialization of shared dialog buttons so that code runs in environments where a window and dom are not available (e.g. a Web Worker context).

R=pupius
DELTA=19  (2 added, 0 deleted, 17 changed)


Revision created by MOE tool push_codebase.
MOE_MIGRATION=1877


yamadatomonori/closure-library,yamadatomonori/closure-library,yamadatomonori/closure-library