Mojo: Start writing some unit tests for mojo::system::Channel.

mojo/system/raw_channel.h

 // Copyright 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.
 
 #ifndef MOJO_SYSTEM_RAW_CHANNEL_H_
 #define MOJO_SYSTEM_RAW_CHANNEL_H_
 
 #include <deque>
 #include <vector>
 
@@ skipping 86 matching lines @@
   bool IsWriteBufferEmpty();
 
  protected:
   // Return values of |[Schedule]Read()| and |[Schedule]WriteNoLock()|.
   enum IOResult {
     IO_SUCCEEDED,
     IO_FAILED,
     IO_PENDING
   };
 
-  class ReadBuffer {
+  class MOJO_SYSTEM_IMPL_EXPORT ReadBuffer {
    public:
     ReadBuffer();
     ~ReadBuffer();
 
     void GetBuffer(char** addr, size_t* size);
 
    private:
     friend class RawChannel;
 
     // We store data from |[Schedule]Read()|s in |buffer_|. The start of
     // |buffer_| is always aligned with a message boundary (we will copy memory
     // to ensure this), but |buffer_| may be larger than the actual number of
     // bytes we have.
     std::vector<char> buffer_;
     size_t num_valid_bytes_;
 
     DISALLOW_COPY_AND_ASSIGN(ReadBuffer);
   };
 
-  class WriteBuffer {
+  class MOJO_SYSTEM_IMPL_EXPORT WriteBuffer {
    public:
     struct Buffer {
       const char* addr;
       size_t size;
     };
 
     WriteBuffer();
     ~WriteBuffer();
 
     void GetBuffers(std::vector<Buffer>* buffers) const;
@@ skipping 104 matching lines @@
   // are only used/invalidated on the I/O thread.
   base::WeakPtrFactory<RawChannel> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(RawChannel);
 };
 
 }  // namespace system
 }  // namespace mojo
 
 #endif  // MOJO_SYSTEM_RAW_CHANNEL_H_