IDL: Remove [InitializedByEventConstructor] from HashChangeEvent
IDL: Remove [InitializedByEventConstructor] from HashChangeEvent

It doesn't have any effect when [EventConstructor] is not specified.

BUG=433179

Review URL: https://codereview.chromium.org/1156643002

git-svn-id: bf5cd6ccde378db821296732a091cfbcf5285fbd@195770 bbb929c8-8fbe-4397-9dbb-9b2b20218538

Pluto-tv/blink-crosswalk,Pluto-tv/blink-crosswalk,Pluto-tv/blink-crosswalk,Pluto-tv/blink-crosswalk,Pluto-tv/blink-crosswalk,Pluto-tv/blink-crosswalk,Pluto-tv/blink-crosswalk,Pluto-tv/blink-crosswalk,Pluto-tv/blink-crosswalk,Pluto-tv/blink-crosswalk