Add a deprecation message for PPAPI WebSocket

Display a console message (in the context of the page) when a WebSocket
is created via the Pepper pp::WebSocket API.

Also add deprecation warnings to the documentation.

Tested by manual verification that the console message is shown when
the PPAPI WebSocket browser_tests are run.

Intent to deprecate thread:!msg/blink-dev/3NYHaxhRs14/XOdUJBvHAwAJ


Change-Id: Ib4631d11cd94cecad6c42e6b3fb1fb81ffc2b7fb
Commit-Queue: Adam Rice <>
Reviewed-by: Nate Chapin <>
Reviewed-by: Yutaka Hirano <>
Reviewed-by: Jochen Eisinger <>
Cr-Original-Commit-Position: refs/heads/master@{#581191}
Cr-Mirrored-Commit: 77d2955c7480d8d51f31c82d512c944385279891
4 files changed