
Remove webkit_mutationobserver.js from externs now that the externs are in javascript/externs.

Also fixed up the type annotation for WebKitMutationObserver and MozMutationObserver constructors.

R=isparrow,acleung
DELTA=99  (2 added, 89 deleted, 8 changed)


Revision created by MOE tool push_codebase.
MOE_MIGRATION=5845


git-svn-id: 818616af560c21f974e3119d89e3310384da871a@2331 b0f006be-c8cd-11de-a2e8-8d36a3108c74

knutwalker/google-closure-compiler,knutwalker/google-closure-compiler