Use relative paths in GN files.

webrtc/video/BUILD.gn

Index: webrtc/video/BUILD.gn
diff --git a/webrtc/video/BUILD.gn b/webrtc/video/BUILD.gn
index 5faf28048e0fb11646c6d2ba24955e89020a87c7..e6f63f25eb7174213a8c1ca04d297613dfe5e3d7 100644
--- a/webrtc/video/BUILD.gn
+++ b/webrtc/video/BUILD.gn
@@ -107,11 +107,11 @@ if (rtc_include_tests) {
       "../modules/video_coding:webrtc_vp9",
       "../system_wrappers",
       "../test:test_common",
+      "../test:test_renderer",
       "../test:test_support",
+      "../test:video_test_common",
       "../voice_engine",
       "//testing/gtest",
-      "//webrtc/test:test_renderer",
-      "//webrtc/test:video_test_common",
     ]
     if (!build_with_chromium && is_clang) {
       # Suppress warnings from the Chromium Clang plugin (bugs.webrtc.org/163).
@@ -126,7 +126,7 @@ if (rtc_include_tests) {
     # gets additional generated targets which would require many lines here to
     # cover (which would be confusing to read and hard to maintain).
     if (!is_android && !is_ios) {
-      visibility = [ "//webrtc:webrtc_perf_tests" ]
+      visibility = [ "..:webrtc_perf_tests" ]
     }
     sources = [
       "full_stack_tests.cc",
@@ -135,9 +135,9 @@ if (rtc_include_tests) {
       ":video_quality_test",
       "../modules/pacing:pacing",
       "../test:field_trial",
+      "../test:test_common",
       "../test:test_support",
       "//testing/gtest",
-      "//webrtc/test:test_common",
     ]
     if (!build_with_chromium && is_clang) {
       # Suppress warnings from the Chromium Clang plugin (bugs.webrtc.org/163).
@@ -233,7 +233,7 @@ if (rtc_include_tests) {
     # gets additional generated targets which would require many lines here to
     # cover (which would be confusing to read and hard to maintain).
     if (!is_android && !is_ios) {
-      visibility = [ "//webrtc:video_engine_tests" ]
+      visibility = [ "..:video_engine_tests" ]
     }
     defines = []
     sources = [