Support WebSocket in WebRequest API.
This CL makes WebRequest API support intercepting the WebSocket handshake
request. Since the handshake is done by means of an HTTP upgrade request, its
flow fits into HTTP-oriented WebRequest model. Additional restriction applies,
that WS request redirects triggered by extensions are ignored.
Note that WebRequest API does *not intercept*:
- Individual messages sent over an established WebSocket connection.
- WebSocket closing connection.
The |details| object reported to extensions uses the newly introduced type of
request: 'websocket'.
BUG=129353
Review-Url: https://codereview.chromium.org/2449913002
Cr-Commit-Position: refs/heads/master@{#451991}
22 files changed
