Fix //chrome/app/test_support dependency on //chrome/browser/policy:path_parser

BUG=

Review URL: https://codereview.chromium.org/1646483002

Cr-Commit-Position: refs/heads/master@{#371790}

chrome/app/BUILD.gn

@@ -322,7 +322,6 @@ source_set("test_support") {
   deps = [
     "//base",
     "//chrome/browser",
-    "//chrome/browser/policy:path_parser",
     "//chrome/child",
     "//chrome/common",
     "//chrome/plugin",
@@ -353,6 +352,10 @@ source_set("test_support") {
     deps += [ "//chrome/browser/chromeos" ]
   }
 
+  if (enable_configuration_policy) {
+    deps += [ "//chrome/browser/policy:path_parser" ]
+  }
+
   if (enable_pdf) {
     deps += [ "//pdf" ]
   }