GN(Android): Fix up webkit_unit_tests to match GYP

third_party/WebKit/Source/web/BUILD.gn

Index: third_party/WebKit/Source/web/BUILD.gn
diff --git a/third_party/WebKit/Source/web/BUILD.gn b/third_party/WebKit/Source/web/BUILD.gn
index 616c314932d63244a275ecf1b2b60dcc1f8982fc..960394b88cbc5e0a6fbbd02b2a1b6cf261dc1ddb 100644
--- a/third_party/WebKit/Source/web/BUILD.gn
+++ b/third_party/WebKit/Source/web/BUILD.gn
@@ -139,4 +139,13 @@ test("webkit_unit_tests") {
     sources += platform_unittest_support_files
     sources += platform_web_unittest_files
   }
+
+  if (is_android) {
+    apk_deps = [
+      "//base:base_java",
+      "//net/android:net_java",
+      "//content/shell/android:copy_content_shell_assets",
+    ]
+    apk_asset_location = "$root_build_dir/content_shell/assets"
+  }
 }