Sync more GN unit tests with GYP.

components/navigation_interception/BUILD.gn

Index: components/navigation_interception/BUILD.gn
diff --git a/components/navigation_interception/BUILD.gn b/components/navigation_interception/BUILD.gn
index 788c2d72cc87e7911f266edcf2399ee4761a4c96..12456ff30d6a1206f8780ca951a6f1a1662046db 100644
--- a/components/navigation_interception/BUILD.gn
+++ b/components/navigation_interception/BUILD.gn
@@ -6,7 +6,7 @@ if (is_android) {
   import("//build/config/android/rules.gni")
 }
 
-static_library("navigation_interception") {
+source_set("navigation_interception") {
   sources = [
     "intercept_navigation_resource_throttle.cc",
     "intercept_navigation_resource_throttle.h",
@@ -45,3 +45,16 @@ if (is_android) {
     jni_package = "navigation_interception"
   }
 }
+
+source_set("unit_tests") {
+  testonly = true
+  sources = [
+    "intercept_navigation_resource_throttle_unittest.cc",
+  ]
+  deps = [
+    ":navigation_interception",
+    "//content/public/browser",
+    "//testing/gmock",
+    "//testing/gtest",
+  ]
+}