fate/webp : add test for lossy compression.

the result of ffmpeg decoding is binary exact with the yuv output of
official decoder (dwebp)
Signed-off-by: James Almer <jamrial@gmail.com>

tests/fate/image.mak

@@ -361,6 +361,12 @@ fate-webp-rgb-lossless: CMD = framecrc -i $(TARGET_SAMPLES)/webp/rgb_lossless.we
 FATE_WEBP += fate-webp-rgba-lossless
 fate-webp-rgba-lossless: CMD = framecrc -i $(TARGET_SAMPLES)/webp/rgba_lossless.webp
 
+FATE_WEBP += fate-webp-rgb-lossy-q80
+fate-webp-rgb-lossy-q80: CMD = framecrc -i $(TARGET_SAMPLES)/webp/rgb_q80.webp
+
+FATE_WEBP += fate-webp-rgba-lossy-q80
+fate-webp-rgba-lossy-q80: CMD = framecrc -i $(TARGET_SAMPLES)/webp/rgba_q80.webp
+
 FATE_WEBP-$(call DEMDEC, IMAGE2, WEBP) += $(FATE_WEBP)
 FATE_IMAGE += $(FATE_WEBP-yes)
 fate-webp: $(FATE_WEBP-yes)

tests/ref/fate/webp-rgb-lossy-q80

+#tb 0: 1/25
+#media_type 0: video
+#codec_id 0: rawvideo
+#dimensions 0: 12x8
+#sar 0: 0/1
+0,          0,          0,        1,      144, 0xf38b5307

tests/ref/fate/webp-rgba-lossy-q80

+#tb 0: 1/25
+#media_type 0: video
+#codec_id 0: rawvideo
+#dimensions 0: 12x8
+#sar 0: 0/1
+0,          0,          0,        1,      240, 0xc56c96c3