Add check_deps rules in DEPS files.

webrtc/modules/video_coding/codecs/vp8/simulcast_unittest.h

Index: webrtc/modules/video_coding/codecs/vp8/simulcast_unittest.h
diff --git a/webrtc/modules/video_coding/codecs/vp8/simulcast_unittest.h b/webrtc/modules/video_coding/codecs/vp8/simulcast_unittest.h
index 9f0dc5ce93a5f339f023d2a538f2e96bd17a7b07..2b2aa5de69f30ca59b702559711f2da5b8fa0245 100644
--- a/webrtc/modules/video_coding/codecs/vp8/simulcast_unittest.h
+++ b/webrtc/modules/video_coding/codecs/vp8/simulcast_unittest.h
@@ -15,6 +15,7 @@
 #include <memory>
 #include <vector>
 
+#include "testing/gtest/include/gtest/gtest.h"
 #include "webrtc/base/checks.h"
 #include "webrtc/common_video/libyuv/include/webrtc_libyuv.h"
 #include "webrtc/modules/video_coding/include/mock/mock_video_codec_interface.h"
@@ -22,8 +23,6 @@
 #include "webrtc/modules/video_coding/codecs/vp8/temporal_layers.h"
 #include "webrtc/video_frame.h"
 
-#include "gtest/gtest.h"
-
 using ::testing::_;
 using ::testing::AllOf;
 using ::testing::Field;