Add net::SourceStream and net::FilterSourceStream

net/filter/mock_source_stream.h

Index: net/filter/mock_source_stream.h
diff --git a/net/filter/mock_source_stream.h b/net/filter/mock_source_stream.h
new file mode 100644
index 0000000000000000000000000000000000000000..9c88bef7cb806a3e75147b16b1c5df257b2c0e01
--- /dev/null
+++ b/net/filter/mock_source_stream.h
@@ -0,0 +1,70 @@
+// Copyright 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_FILTER_MOCK_SOURCE_STREAM_H_
+#define NET_FILTER_MOCK_SOURCE_STREAM_H_
+
+#include <queue>
+#include <string>
+
+#include "base/macros.h"
+#include "base/memory/ref_counted.h"
+#include "net/base/completion_callback.h"
+#include "net/base/net_errors.h"
+#include "net/filter/source_stream.h"
+
+namespace net {
+
+class IOBuffer;
+
+// A SourceStream implementation used in tests. This allows tests to specify
+// what data to return for each Read() call.
+class MockSourceStream : public SourceStream {
+ public:
+  enum Mode {
+    SYNC,
+    ASYNC,
+  };
+  MockSourceStream();
+  // The destructor will crash in debug build if there is any pending read.
+  ~MockSourceStream() override;
+
+  // SourceStream implementation
+  int Read(IOBuffer* dest_buffer,
+           int buffer_size,
+           const CompletionCallback& callback) override;
+  std::string Description() const override;
+
+  // Enqueues a result to be returned by |Read|. This method does not make a
+  // copy of |data|, so |data| must outlive this object. If |mode| is SYNC,
+  // |Read| will return the supplied data synchronously; otherwise, consumer
+  // needs to call |CompleteNextRead|
+  void AddReadResult(const char* data, int len, Error error, Mode mode);
+
+  // Completes a pending Read() call. Crash in debug build if there is no
+  // pending read.
+  void CompleteNextRead();
+
+ private:
+  struct QueuedResult {
+    QueuedResult(const char* data, int len, Error error, Mode mode);
+
+    const char* data;
+    const int len;
+    const Error error;
+    const Mode mode;
+  };
+
+  std::queue<QueuedResult> results_;
+  bool awaiting_completion_;
+  scoped_refptr<IOBuffer> dest_buffer_;
+  CompletionCallback callback_;
+  int dest_buffer_size_;
+
+  DISALLOW_COPY_AND_ASSIGN(MockSourceStream);
+};
+
+}  // namespace net
+
+#endif  // NET_FILTER_MOCK_SOURCE_STREAM_H_