[Chromoting] Add unit tests for up- and down-scaling.

remoting/base/decoder_vp8_unittest.cc

Index: remoting/base/decoder_vp8_unittest.cc
diff --git a/remoting/base/decoder_vp8_unittest.cc b/remoting/base/decoder_vp8_unittest.cc
index e75071477555e934a7fc7ce0dc1655dee4ae07e2..ab0607fc35135b4aebce6e23797fbca8ddbc45bc 100644
--- a/remoting/base/decoder_vp8_unittest.cc
+++ b/remoting/base/decoder_vp8_unittest.cc
@@ -10,19 +10,65 @@
 
 namespace remoting {
 
-TEST(DecoderVp8Test, EncodeAndDecode) {
-  EncoderVp8 encoder;
-  DecoderVp8 decoder;
-  TestEncoderDecoder(&encoder, &decoder, false);
+class DecoderVp8Test : public testing::Test {
+ protected:
+  EncoderVp8 encoder_;
+  DecoderVp8 decoder_;
+
+  void TestGradient(int screen_width, int screen_height,
+                    int view_width, int view_height,
+                    double max_error_limit, double mean_error_limit) {
+    TestEncoderDecoderGradient(&encoder_, &decoder_,
+                               SkISize::Make(screen_width, screen_height),
+                               SkISize::Make(view_width, view_height),
+                               max_error_limit, mean_error_limit);
+  }
+};
+
+TEST_F(DecoderVp8Test, EncodeAndDecode) {
+  TestEncoderDecoder(&encoder_, &decoder_, false);
 }
 
 // Check that encoding and decoding a particular frame doesn't change the
 // frame too much. The frame used is a gradient, which does not contain sharp
 // transitions, so encoding lossiness should not be too high.
-TEST(DecoderVp8Test, Gradient) {
-  EncoderVp8 encoder;
-  DecoderVp8 decoder;
-  TestEncoderDecoderGradient(&encoder, &decoder, 0.03, 0.01);
+TEST_F(DecoderVp8Test, Gradient) {
+  TestGradient(320, 240, 320, 240, 0.03, 0.01);
+}
+
+TEST_F(DecoderVp8Test, GradientScaleUpEvenToEven) {
+  TestGradient(320, 240, 640, 480, 0.04, 0.02);
+}
+
+TEST_F(DecoderVp8Test, GradientScaleUpEvenToOdd) {
+  TestGradient(320, 240, 641, 481, 0.04, 0.02);
+}
+
+TEST_F(DecoderVp8Test, GradientScaleUpOddToEven) {
+  TestGradient(321, 241, 640, 480, 0.04, 0.02);
+}
+
+TEST_F(DecoderVp8Test, GradientScaleUpOddToOdd) {
+  TestGradient(321, 241, 641, 481, 0.04, 0.02);
+}
+
+TEST_F(DecoderVp8Test, GradientScaleDownEvenToEven) {
+  TestGradient(320, 240, 160, 120, 0.04, 0.02);
+}
+
+TEST_F(DecoderVp8Test, GradientScaleDownEvenToOdd) {
+  // TODO(simonmorris): The maximum error is non-deterministic.
+  // The mean error is not too high, which suggests that the problem is
+  // restricted to a small area of the output image. See crbug.com/139437.
+  TestGradient(320, 240, 161, 121, 1.0, 0.02);
+}
+
+TEST_F(DecoderVp8Test, GradientScaleDownOddToEven) {
+  TestGradient(321, 241, 160, 120, 0.04, 0.02);
+}
+
+TEST_F(DecoderVp8Test, GradientScaleDownOddToOdd) {
+  TestGradient(321, 241, 161, 121, 0.04, 0.02);
 }
 
 }  // namespace remoting