Add DecodedImageCallback::Decoded() function with custom decode time value.

webrtc/video/video_decoder_unittest.cc

Index: webrtc/video/video_decoder_unittest.cc
diff --git a/webrtc/video/video_decoder_unittest.cc b/webrtc/video/video_decoder_unittest.cc
index be09b191ac1813596c62439f298608c43a1948ed..63227c880c8a5c7a2ef3507f034bbdaf894b4769 100644
--- a/webrtc/video/video_decoder_unittest.cc
+++ b/webrtc/video/video_decoder_unittest.cc
@@ -11,6 +11,7 @@
 #include "webrtc/video_decoder.h"
 
 #include "testing/gtest/include/gtest/gtest.h"
+#include "webrtc/base/checks.h"
 #include "webrtc/modules/video_coding/codecs/interface/video_error_codes.h"
 
 namespace webrtc {
@@ -148,6 +149,11 @@ TEST_F(VideoDecoderSoftwareFallbackWrapperTest,
        ForwardsRegisterDecodeCompleteCallback) {
   class FakeDecodedImageCallback : public DecodedImageCallback {
     int32_t Decoded(VideoFrame& decodedImage) override { return 0; }
+    int32_t Decoded(
+        webrtc::VideoFrame& decodedImage, int64_t decode_time_ms) override {
+      RTC_NOTREACHED();
+      return Decoded(decodedImage);
+    }
   } callback, callback2;
 
   VideoCodec codec = {};