Copy the (early prototype of) remoting in Chrome into the public tree....

remoting/host/differ_block_unittest.cc

+// 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.
+
+#include "media/base/data_buffer.h"
+#include "remoting/host/differ_block.h"
+#include "testing/gmock/include/gmock/gmock.h"
+
+namespace remoting {
+
+static const int kWidth = 32;
+static const int kHeight = 32;
+static const int kBytesPerPixel = 3;
+
+static void GenerateData(uint8* data, int size) {
+  for (int i = 0; i < size; ++i) {
+    data[i] = i;
+  }
+}
+
+class EncodeDoneHandler
+    : public base::RefCountedThreadSafe<EncodeDoneHandler> {
+ public:
+  MOCK_METHOD0(EncodeDone, void());
+};
+
+TEST(BlockDifferenceTest, BlockDifference) {
+  // Prepare 2 blocks to compare.
+  uint8 block1[kHeight * kWidth * kBytesPerPixel];
+  uint8 block2[kHeight * kWidth * kBytesPerPixel];
+  GenerateData(block1, sizeof(block1));
+  memcpy(block2, block1, sizeof(block2));
+
+  // These blocks should match.
+  int same = BlockDifference(block1, block2, kWidth * kBytesPerPixel);
+  EXPECT_EQ(0, same);
+
+  // Change block2 a little.
+  block2[7] += 3;
+  block2[sizeof(block2)-1] -= 5;
+  // These blocks should not match.  The difference should be 8.
+  int not_same = BlockDifference(block1, block2, kWidth * kBytesPerPixel);
+  EXPECT_EQ(8, not_same);
+}
+
+}  // namespace remoting