Reland r187230: Implement the Stream registry in content

content/browser/streams/stream_registry.cc

+// Copyright (c) 2013 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.
+
+#include "content/browser/streams/stream_registry.h"
+
+#include "content/browser/streams/stream.h"
+
+namespace content {
+
+StreamRegistry::StreamRegistry() {
+}
+
+StreamRegistry::~StreamRegistry() {
+}
+
+void StreamRegistry::RegisterStream(scoped_refptr<Stream> stream) {
+  DCHECK(CalledOnValidThread());
+  DCHECK(stream);
+  DCHECK(!stream->url().is_empty());
+  streams_[stream->url()] = stream;
+}
+
+scoped_refptr<Stream> StreamRegistry::GetStream(const GURL& url) {
+  DCHECK(CalledOnValidThread());
+  StreamMap::const_iterator stream = streams_.find(url);
+  if (stream != streams_.end())
+    return stream->second;
+
+  return NULL;
+}
+
+bool StreamRegistry::CloneStream(const GURL& url, const GURL& src_url) {
+  DCHECK(CalledOnValidThread());
+  scoped_refptr<Stream> stream(GetStream(src_url));
+  if (stream) {
+    streams_[url] = stream;
+    return true;
+  }
+  return false;
+}
+
+void StreamRegistry::UnregisterStream(const GURL& url) {
+  DCHECK(CalledOnValidThread());
+  streams_.erase(url);
+}
+
+}  // namespace content