Add blink::WebSocketHandshakeThrottle

third_party/WebKit/public/platform/WebSocketHandshakeThrottle.h

Index: third_party/WebKit/public/platform/WebSocketHandshakeThrottle.h
diff --git a/third_party/WebKit/public/platform/WebSocketHandshakeThrottle.h b/third_party/WebKit/public/platform/WebSocketHandshakeThrottle.h
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+// Copyright 2017 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+//
+// WebSocketHandshakeThrottle provides a facility for embedders to delay
+// WebSocket connection establishment. Specifically, at the same time as the
+// handshake is started blink::Platform::CreateWebSocketHandshakeThrottle() will
+// be called. If a non-null WebSocketHandshakeThrottle is returned then
+// ThrottleHandshake() will be called on it. If the result is error then the
+// handshake will be aborted, and a connection error will be reported to
+// Javascript. If the throttle hasn't reported a result when the WebSocket
+// handshake succeeds then Blink will wait for the throttle result before
+// reporting the connection is open to Javascript.
+
+#ifndef WebSocketHandshakeThrottle_h
+#define WebSocketHandshakeThrottle_h
+
+#include "public/platform/WebCallbacks.h"
+
+namespace blink {
+
+class WebURL;
+class WebLocalFrame;
+class WebString;
+
+// Embedders can implement this class to delay WebSocket connections.
+class WebSocketHandshakeThrottle {
+ public:
+  // Destruction implies that the handshake has been aborted. Any ongoing work
+  // should be cleaned up if possible.
+  virtual ~WebSocketHandshakeThrottle() {}
+
+  // The WebCallbacks OnSuccess or OnError should be called asychronously to
+  // permit Javascript to use the connection or not. OnError should be passed
+  // a message to be displayed on the console indicating why the handshake was
+  // blocked. This object will be destroyed synchronously inside the
+  // callbacks. Callbacks must not be called after this object has been
+  // destroyed.
+  virtual void ThrottleHandshake(const WebURL&,
+                                 WebLocalFrame*,
+                                 WebCallbacks<void, const WebString&>*) = 0;
+};
+
+}  // namespace blink
+
+#endif  // WebSocketHandshakeThrottle_h