Omit save_password_infobar.cc from the build when unused

chrome/test/BUILD.gn

Index: chrome/test/BUILD.gn
diff --git a/chrome/test/BUILD.gn b/chrome/test/BUILD.gn
index 86da6deb0a101d1b8d4dc3b8e7137c3fe762e560..17a7d8315773c794eca179425e40d81cace59c66 100644
--- a/chrome/test/BUILD.gn
+++ b/chrome/test/BUILD.gn
@@ -1785,6 +1785,12 @@ if (!is_android) {
       # other things like the ui and startup tests. *shrug*
       ldflags = [ "-Wl,-ObjC" ]
     }
+    if (is_mac || is_android) {
+      sources += rebase_path(
+              chrome_tests_unit_gypi_values.chrome_unit_tests_mac_android_sources,
+              ".",
+              "//chrome")
+    }
     if (!is_mac && !is_ios) {
       deps += [
         "//chrome/tools/convert_dict:lib",