GN: Refactor modules_unittests to eliminate package boundary violations.

webrtc/modules/bitrate_controller/BUILD.gn

 # Copyright (c) 2014 The WebRTC project authors. All Rights Reserved.
 #
 # Use of this source code is governed by a BSD-style license
 # that can be found in the LICENSE file in the root of the source
 # tree. An additional intellectual property rights grant can be found
 # in the file PATENTS.  All contributing project authors may
 # be found in the AUTHORS file in the root of the source tree.
 
 import("../../build/webrtc.gni")
 
@@ skipping 24 matching lines @@
     # Suppress warnings from the Chromium Clang plugin (bugs.webrtc.org/163).
     suppressed_configs += [ "//build/config/clang:find_bad_constructs" ]
   }
 
   deps = [
     "../../base:rtc_base_approved",
     "../../system_wrappers",
     "../rtp_rtcp",
   ]
 }
+
+if (rtc_include_tests) {
+  rtc_source_set("bitrate_controller_unittests") {
+    testonly = true
+    sources = [
+      "bitrate_controller_unittest.cc",
+      "send_side_bandwidth_estimation_unittest.cc",
+    ]
+    deps = [
+      ":bitrate_controller",
+      "../../test:field_trial",
+      "../../test:test_support",
+      "../remote_bitrate_estimator:remote_bitrate_estimator",
+      "//testing/gmock",
+    ]
+    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" ]
+    }
+  }
+}