GitLab

The specification defines that PushEvents can be initialized with a
data member that is of type PushMessageDataInit, rather than an actual
PushMessageData object. This allows us to remove the constructor from
the PushMessageData object entirely, aligning with the specification.

https://w3c.github.io/push-api/#pushmessagedata-interface

This CL also implements the following pull requests, which defines the
PushMessageDataInit type to also encapsulate ArrayBuffer(View)?.

https://github.com/w3c/push-api/pull/160

Note that the PushMessageData object has not shipped to the world yet.

R=mvanouwerkerk
BUG=

Review URL: https://codereview.chromium.org/1311853002

git-svn-id: svn://svn.chromium.org/blink/trunk@201129 bbb929c8-8fbe-4397-9dbb-9b2b20218538