Introduce WebSocketDeflateParameters.

This CL introduces WebSocketDeflateParameters which represents WebSocket
"permessage-deflate" extension parameters. The class will also be used
by WebSocketEncoder sitting on net/server in the future.

This CL doesn't change the behavior.

BUG=523228

Review URL: https://codereview.chromium.org/1324113002

Cr-Commit-Position: refs/heads/master@{#348567}
diff --git a/net/net.gypi b/net/net.gypi
index 3f21d89..936e802 100644
--- a/net/net.gypi
+++ b/net/net.gypi
@@ -1724,6 +1724,7 @@
       'url_request/view_cache_helper_unittest.cc',
       'websockets/websocket_basic_stream_test.cc',
       'websockets/websocket_channel_test.cc',
+      'websockets/websocket_deflate_parameters_test.cc',
       'websockets/websocket_deflate_predictor_impl_test.cc',
       'websockets/websocket_deflate_stream_test.cc',
       'websockets/websocket_deflater_test.cc',
@@ -1842,6 +1843,8 @@
       "websockets/websocket_basic_stream.h",
       "websockets/websocket_channel.cc",
       "websockets/websocket_channel.h",
+      "websockets/websocket_deflate_parameters.cc",
+      "websockets/websocket_deflate_parameters.h",
       "websockets/websocket_deflate_predictor.h",
       "websockets/websocket_deflate_predictor_impl.cc",
       "websockets/websocket_deflate_predictor_impl.h",