[Courgette] Refactor: Add CourgetteFlow; improve courgette_tool.cc help text.

courgette/streams.h

 // Copyright (c) 2011 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.
 
 // Streams classes.
 //
 // These memory-resident streams are used for serializing data into a sequential
 // region of memory.
 // Streams are divided into SourceStreams for reading and SinkStreams for
 // writing.  Streams are aggregated into Sets which allows several streams to be
@@ skipping 15 matching lines @@
 
 
 namespace courgette {
 
 class SourceStream;
 class SinkStream;
 
 // Maximum number of streams in a stream set.
 static const unsigned int kMaxStreams = 10;
 
+// A simple interface for reading binary data.
+class BasicBuffer {
+ public:
+  BasicBuffer() {}
+  virtual ~BasicBuffer() {}
+  virtual const uint8_t* data() const = 0;
+  virtual size_t length() const = 0;
+};
+
 // A SourceStream allows a region of memory to be scanned by a sequence of Read
 // operations.  The stream does not own the memory.
 class SourceStream {
  public:
   SourceStream() : start_(NULL), end_(NULL), current_(NULL) {}
 
   // Initializes the SourceStream to yield the bytes at |pointer|.  The caller
   // still owns the memory at |pointer| and should free the memory only after
   // the last use of the stream.
   void Init(const void* pointer, size_t length) {
@@ skipping 181 matching lines @@
 
  private:
   CheckBool CopyHeaderTo(SinkStream* stream) WARN_UNUSED_RESULT;
 
   size_t count_;
   SinkStream streams_[kMaxStreams];
 
   DISALLOW_COPY_AND_ASSIGN(SinkStreamSet);
 };
 
-}  // namespace
+}  // namespace courgette
+
 #endif  // COURGETTE_STREAMS_H_