Resubmit - Use SSE2 block differ for chromoting

remoting/host/differ_block_internal.h

Index: remoting/host/differ_block_internal.h
diff --git a/remoting/host/differ_block_internal.h b/remoting/host/differ_block_internal.h
new file mode 100644
index 0000000000000000000000000000000000000000..d0ddce0efd3002f9a87950a9a0e738e55fae320b
--- /dev/null
+++ b/remoting/host/differ_block_internal.h
@@ -0,0 +1,25 @@
+// 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.
+
+// This header file is used only differ_block.h. It defines the SSE2 rountines
+// for finding block difference.
+
+#ifndef REMOTING_HOST_DIFFER_BLOCK_INTERNAL_H_
+#define REMOTING_HOST_DIFFER_BLOCK_INTERNAL_H_
+
+#include "base/basictypes.h"
+
+namespace remoting {
+
+// Find block difference of dimension 16x16.
+extern int BlockDifference_SSE2_W16(const uint8* image1, const uint8* image2,
+                                    int stride);
+
+// Find block difference of dimension 32x32.
+extern int BlockDifference_SSE2_W32(const uint8* image1, const uint8* image2,
+                                    int stride);
+
+}  // namespace remoting
+
+#endif  // REMOTING_HOST_DIFFER_BLOCK_INTERNAL_H_