Add browsertest for Flash permission prompt

chrome/test/BUILD.gn

Index: chrome/test/BUILD.gn
diff --git a/chrome/test/BUILD.gn b/chrome/test/BUILD.gn
index be7d4db8c8c263a6bf120a4766ad32b28907cc51..85f0cb8d257963508f1bddb59970620ce2eb5e5e 100644
--- a/chrome/test/BUILD.gn
+++ b/chrome/test/BUILD.gn
@@ -1559,8 +1559,8 @@ test("browser_tests") {
       "../browser/interstitials/security_interstitial_page_test_utils.h",
       "../browser/invalidation/profile_invalidation_provider_factory_browsertest.cc",
       "../browser/lifetime/browser_close_manager_browsertest.cc",
-      "../browser/loadtimes_extension_bindings_browsertest.cc",
       "../browser/loader/chrome_resource_dispatcher_host_delegate_browsertest.cc",
+      "../browser/loadtimes_extension_bindings_browsertest.cc",
       "../browser/locale_tests_browsertest.cc",
       "../browser/media/defer_background_media_browsertest.cc",
       "../browser/media/encrypted_media_browsertest.cc",
@@ -1621,6 +1621,7 @@ test("browser_tests") {
       "../browser/pdf/pdf_extension_test_util.cc",
       "../browser/pdf/pdf_extension_test_util.h",
       "../browser/permissions/permission_request_manager_browsertest.cc",
+      "../browser/permissions/permissions_browsertest.cc",
       "../browser/plugins/plugin_power_saver_browsertest.cc",
       "../browser/policy/cloud/cloud_policy_browsertest.cc",
       "../browser/policy/cloud/cloud_policy_manager_browsertest.cc",