GN: Refactor modules_unittests to eliminate package boundary violations.

webrtc/modules/video_processing/BUILD.gn

Index: webrtc/modules/video_processing/BUILD.gn
diff --git a/webrtc/modules/video_processing/BUILD.gn b/webrtc/modules/video_processing/BUILD.gn
index 5ab3f457ecdc108398d3b2b29809b551bbf54ed6..5da0ae89ee2606cbfeff03020e2757f63f3aee81 100644
--- a/webrtc/modules/video_processing/BUILD.gn
+++ b/webrtc/modules/video_processing/BUILD.gn
@@ -89,3 +89,22 @@ if (rtc_build_with_neon) {
     }
   }
 }
+
+if (rtc_include_tests) {
+  rtc_source_set("video_processing_unittests") {
+    testonly = true
+    sources = [
+      "test/denoiser_test.cc",
+    ]
+    deps = [
+      ":video_processing",
+      "../../common_video:common_video",
+      "../../test:test_support",
+      "../../test:video_test_common",
+    ]
+    if (!build_with_chromium && is_clang) {
+      # Suppress warnings from the Chromium Clang plugin (bugs.webrtc.org/163).
+      suppressed_configs += [ "//build/config/clang:find_bad_constructs" ]
+    }
+  }
+}