Remove dependency from SignInBrowsertest on tracing events watching

chrome/browser/ui/webui/chromeos/login/signin_screen_handler.cc

 // Copyright (c) 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/ui/webui/chromeos/login/signin_screen_handler.h"
 
 #include <stddef.h>
 
 #include <algorithm>
 #include <vector>
@@ skipping 95 matching lines @@
 // Timeout used to prevent infinite connecting to a flaky network.
 const int kConnectingTimeoutSec = 60;
 
 // Max number of Gaia Reload to Show Proxy Auth Dialog.
 const int kMaxGaiaReloadForProxyAuthDialog = 3;
 
 // Type of the login screen UI that is currently presented to user.
 const char kSourceGaiaSignin[] = "gaia-signin";
 const char kSourceAccountPicker[] = "account-picker";
 
+base::LazyInstance<base::Closure> g_ui_shown_callback_for_testing_ =
+    LAZY_INSTANCE_INITIALIZER;

[stevenjb, 2016/10/14 17:31:55]

No trailing _ in file local variables.

If this is just a Closure*, we don't need to use LazyInstance:

base::Closure* g_ui_shown_callback_for_testing = nullptr;

Then below:

if (g_ui_shown_callback_for_testing)
  g_ui_shown_callback_for_testing->Run();

[Primiano Tucci (use gerrit), 2016/10/14 17:42:56]

I am not sure I follow, how do you expect the g_closure ptr to be set?
Definitely It cannot be set to a pointer to some stack allocated thing.
The only alternative way I see is doing
g_closure = new base::Closure ....

but this will make memory sanitizers unhappy because will be seen as a leak.
At this point you could add a ANNOTATE_LEAKING_OBJECT_PTR, but at this point you
now have more complexity than lazyinstance itself.

+
 static bool Contains(const std::vector<std::string>& container,
                      const std::string& value) {
   return std::find(container.begin(), container.end(), value) !=
          container.end();
 }
 
 class CallOnReturn {
  public:
   explicit CallOnReturn(const base::Closure& callback)
       : callback_(callback), call_scheduled_(false) {}
@@ skipping 231 matching lines @@
   // thus others need to be switched to default locale.
   // Otherwise they will end up using another user's locale to log in.
   if (!succeed) {
     DVLOG(0) << "SetUserInputMethod('" << username
              << "'): failed to set user layout. Switching to default.";
 
     ime_state->SetInputMethodLoginDefault();
   }
 }
 
+// static
+void SigninScreenHandler::SetCallbackOnUiShownForTesting(
+    base::Closure callback) {
+  DCHECK(g_ui_shown_callback_for_testing_.Get().is_null());
+  g_ui_shown_callback_for_testing_.Get() = callback;
+}
+
 void SigninScreenHandler::DeclareLocalizedValues(
     ::login::LocalizedValuesBuilder* builder) {
   // Format numbers to be used on the pin keyboard.
   for (int j = 0; j <= 9; j++) {
     builder->Add("pinKeyboard" + base::IntToString(j),
                  base::FormatNumber(int64_t{j}));
   }
 
   builder->Add("passwordHint", IDS_LOGIN_POD_EMPTY_PASSWORD_TEXT);
   builder->Add("pinKeyboardPlaceholderPin",
@@ skipping 872 matching lines @@
           << "webui_visible_: " << webui_visible_;
   if (!webui_visible_) {
     // There might be multiple messages from OOBE UI so send notifications after
     // the first one only.
     content::NotificationService::current()->Notify(
         chrome::NOTIFICATION_LOGIN_OR_LOCK_WEBUI_VISIBLE,
         content::NotificationService::AllSources(),
         content::NotificationService::NoDetails());
     TRACE_EVENT_ASYNC_END0(
         "ui", "ShowLoginWebUI", LoginDisplayHostImpl::kShowLoginWebUIid);
+    if (!g_ui_shown_callback_for_testing_.Get().is_null())
+      g_ui_shown_callback_for_testing_.Get().Run();
   }
   webui_visible_ = true;
   if (preferences_changed_delayed_)
     OnPreferencesChanged();
 }
 
 void SigninScreenHandler::HandleCancelPasswordChangedFlow(
     const AccountId& account_id) {
   if (account_id.is_valid()) {
     RecordReauthReason(account_id, ReauthReason::PASSWORD_UPDATE_SKIPPED);
@@ skipping 224 matching lines @@
 }
 
 void SigninScreenHandler::OnFeedbackFinished() {
   CallJS("login.UnrecoverableCryptohomeErrorScreen.resumeAfterFeedbackUI");
 
   // Recreate user's cryptohome after the feedback is attempted.
   HandleResyncUserData();
 }
 
 }  // namespace chromeos