Added merge session request throttle for XHR requests

chrome/browser/chromeos/login/merge_session_xhr_request_waiter.cc

Index: chrome/browser/chromeos/login/merge_session_xhr_request_waiter.cc
diff --git a/chrome/browser/chromeos/login/merge_session_xhr_request_waiter.cc b/chrome/browser/chromeos/login/merge_session_xhr_request_waiter.cc
new file mode 100644
index 0000000000000000000000000000000000000000..e0b38615d27e0217264effc850094cb471cf867c
--- /dev/null
+++ b/chrome/browser/chromeos/login/merge_session_xhr_request_waiter.cc
@@ -0,0 +1,93 @@
+// 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/chromeos/login/merge_session_xhr_request_waiter.h"
+
+#include "base/bind.h"
+#include "base/lazy_instance.h"
+#include "base/logging.h"
+#include "base/memory/weak_ptr.h"
+#include "base/message_loop/message_loop.h"
+#include "chrome/browser/chromeos/login/oauth2_login_manager.h"
+#include "chrome/browser/chromeos/login/oauth2_login_manager_factory.h"
+#include "content/public/browser/browser_thread.h"
+
+using content::BrowserThread;
+
+namespace chromeos {
+
+namespace {
+
+// Maximum time for delaying XHR requests.
+const int kMaxRequestWaitTimeMS = 10000;
+
+}
+
+MergeSessionXHRRequestWaiter::MergeSessionXHRRequestWaiter(
+    Profile* profile,
+    const MergeSessionThrottle::CompletionCallback& callback)
+   : profile_(profile),
+     callback_(callback),
+     weak_ptr_factory_(this) {
+}
+
+MergeSessionXHRRequestWaiter::~MergeSessionXHRRequestWaiter() {
+  chromeos::OAuth2LoginManager* manager =
+      chromeos::OAuth2LoginManagerFactory::GetInstance()->GetForProfile(
+          profile_);
+  if (manager)
+    manager->RemoveObserver(this);
+}
+
+void MergeSessionXHRRequestWaiter::StartWaiting() {
+  OAuth2LoginManager* manager =
+      OAuth2LoginManagerFactory::GetInstance()->GetForProfile(profile_);
+  if (manager && manager->ShouldBlockTabLoading()) {
+    DVLOG(1) << "Waiting for XHR request throttle";
+    manager->AddObserver(this);
+    BrowserThread::PostDelayedTask(
+        BrowserThread::UI, FROM_HERE,
+        base::Bind(&MergeSessionXHRRequestWaiter::OnTimeout,
+                   weak_ptr_factory_.GetWeakPtr()),
+        base::TimeDelta::FromMilliseconds(kMaxRequestWaitTimeMS));
+  } else {
+    NotifyBlockingDone();
+  }
+}
+
+void MergeSessionXHRRequestWaiter::OnSessionRestoreStateChanged(
+    Profile* user_profile,
+    OAuth2LoginManager::SessionRestoreState state) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+
+  OAuth2LoginManager* manager =
+      OAuth2LoginManagerFactory::GetInstance()->GetForProfile(profile_);
+  DVLOG(1) << "Merge session throttle should "
+           << (!manager->ShouldBlockTabLoading() ?
+                  " NOT" : "")
+           << " be blocking now, "
+           << state;
+  if (!manager->ShouldBlockTabLoading()) {
+    DVLOG(1) << "Unblocking XHR request throttledue to session merge";

[xiyuan, 2013/12/19 01:45:41]

nit: throttledue -> throttle due

[zel, 2013/12/19 23:28:02]

Done.

+    manager->RemoveObserver(this);
+    NotifyBlockingDone();
+  }
+}
+
+void MergeSessionXHRRequestWaiter::OnTimeout() {
+  DVLOG(1) << "Unblocking XHR request throttle due to timeout";
+  NotifyBlockingDone();
+}
+
+void MergeSessionXHRRequestWaiter::NotifyBlockingDone() {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+  if (!callback_.is_null()) {
+    BrowserThread::PostTask(
+        BrowserThread::IO, FROM_HERE, callback_);
+  }
+  weak_ptr_factory_.InvalidateWeakPtrs();
+  base::MessageLoop::current()->DeleteSoon(FROM_HERE, this);
+}
+
+}  // namespace chromeos