Relanding the language detection.

chrome/test/ui_test_utils.cc

Index: chrome/test/ui_test_utils.cc
===================================================================
--- chrome/test/ui_test_utils.cc	(revision 35721)
+++ chrome/test/ui_test_utils.cc	(working copy)
@@ -254,6 +254,33 @@
   DISALLOW_COPY_AND_ASSIGN(SimpleNotificationObserver);
 };
 
+class LanguageDetectionNotificationObserver : public NotificationObserver {
+ public:
+  explicit LanguageDetectionNotificationObserver(
+      RenderViewHost* render_view_host) {
+    registrar_.Add(this, NotificationType::TAB_LANGUAGE_DETERMINED,
+                  Source<RenderViewHost>(render_view_host));
+    ui_test_utils::RunMessageLoop();
+  }
+
+  virtual void Observe(NotificationType type,
+                       const NotificationSource& source,
+                       const NotificationDetails& details) {
+    language_ = *(Details<std::string>(details).ptr());
+    MessageLoopForUI::current()->Quit();
+  }
+
+  std::string language() const {
+    return language_;
+  }
+
+ private:
+  NotificationRegistrar registrar_;
+  std::string language_;
+
+  DISALLOW_COPY_AND_ASSIGN(LanguageDetectionNotificationObserver);
+};
+
 class FindInPageNotificationObserver : public NotificationObserver {
  public:
   explicit FindInPageNotificationObserver(TabContents* parent_tab)
@@ -484,6 +511,11 @@
       browser);
 }
 
+std::string WaitForLanguageDetection(TabContents* tab) {
+  LanguageDetectionNotificationObserver observer(tab->render_view_host());
+  return observer.language();
+}
+
 int FindInPage(TabContents* tab_contents, const string16& search_string,
                bool forward, bool match_case, int* ordinal) {
   tab_contents->StartFinding(search_string, forward, match_case);