Server push cancellation: add PushPromiseHelper which reflects information on the push promise.

net/spdy/server_push_delegate.h

Index: net/spdy/server_push_delegate.h
diff --git a/net/spdy/server_push_delegate.h b/net/spdy/server_push_delegate.h
new file mode 100644
index 0000000000000000000000000000000000000000..52e52946243ba4a4d050d9b72790f463cc1e71b0
--- /dev/null
+++ b/net/spdy/server_push_delegate.h
@@ -0,0 +1,37 @@
+// Copyright (c) 2016 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.
+
+#ifndef NET_SPDY_SERVER_PUSH_DELEGATE_H_
+#define NET_SPDY_SERVER_PUSH_DELEGATE_H_
+
+#include "net/base/net_export.h"
+#include "url/gurl.h"
+
+namespace net {
+
+// An interface to a class that should be notified when session receives server
+// push.
+class NET_EXPORT_PRIVATE ServerPushDelegate {
+ public:
+  // An interface to a class that reflects information on the pushed request.
+  class NET_EXPORT ServerPushHelper {
+   public:
+    virtual ~ServerPushHelper() {}
+
+    // Cancels the push if it is not claimed yet.
+    virtual void Cancel() = 0;
+
+    // Gets the URL of the pushed request.
+    virtual const GURL& GetURL() = 0;
+  };
+
+  virtual ~ServerPushDelegate() {}
+
+  // Invoked by session when a push promise has been received.
+  virtual void OnPush(std::unique_ptr<ServerPushHelper> push_helper) = 0;
+};
+
+}  // namespace net
+
+#endif  // NET_SPDY_PUSH_DELEGATE_H_