Pepper audio basic functionality unit test, take 3.
Also changed TestSink to be derived from IPC::Channel and made MockRenderThread service AddFilter/RemoveFilter, so that it can be used by MessageFilters.

Review URL: http://codereview.chromium.org/1591009

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@43623 0039d316-1c4b-4281-b951-d872f2087c98


CrOS-Libchrome-Original-Commit: 90b721e6713f6429a24fe03d4f0dbab588f7dc46
diff --git a/ipc/ipc_channel.h b/ipc/ipc_channel.h
index a7a9a34..d1dbd03 100644
--- a/ipc/ipc_channel.h
+++ b/ipc/ipc_channel.h
@@ -1,4 +1,4 @@
-// Copyright (c) 2006-2008 The Chromium Authors. All rights reserved.
+// Copyright (c) 2010 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.
 
@@ -96,6 +96,13 @@
   int GetClientFileDescriptor() const;
 #endif  // defined(OS_POSIX)
 
+ protected:
+  // Used in Chrome by the TestSink to provide a dummy channel implementation
+  // for testing. TestSink overrides the "interesting" functions in Channel so
+  // no actual implementation is needed. This will cause un-overridden calls to
+  // segfault. Do not use outside of test code!
+  Channel() : channel_impl_(0) { }
+
  private:
   // PIMPL to which all channel calls are delegated.
   class ChannelImpl;