Revert of Deprecate native and extension notification delegates.

chrome/browser/notifications/web_notification_delegate.cc

Index: chrome/browser/notifications/web_notification_delegate.cc
diff --git a/chrome/browser/notifications/web_notification_delegate.cc b/chrome/browser/notifications/web_notification_delegate.cc
index a99bad6e06a9cfd40ff122a91c63c5be223f93bc..8d4e792eb4d48b3ef517254fdb88c3ccac68cfd7 100644
--- a/chrome/browser/notifications/web_notification_delegate.cc
+++ b/chrome/browser/notifications/web_notification_delegate.cc
@@ -7,11 +7,27 @@
 #include "base/feature_list.h"
 #include "base/metrics/histogram_macros.h"
 #include "base/strings/nullable_string16.h"
-#include "chrome/browser/notifications/notification_common.h"
 #include "chrome/browser/notifications/notification_display_service.h"
 #include "chrome/browser/notifications/notification_display_service_factory.h"
 #include "chrome/browser/profiles/profile.h"
+#include "chrome/browser/ui/browser.h"
+#include "chrome/browser/ui/browser_list.h"
+#include "chrome/browser/ui/browser_window.h"
+#include "chrome/browser/ui/exclusive_access/exclusive_access_context.h"
+#include "chrome/browser/ui/exclusive_access/exclusive_access_manager.h"
+#include "chrome/browser/ui/tabs/tab_strip_model.h"
+#include "content/public/browser/web_contents.h"
+#include "ui/message_center/notifier_settings.h"
 
+using message_center::NotifierId;
+
+namespace features {
+
+const base::Feature kAllowFullscreenWebNotificationsFeature{
+  "FSNotificationsWeb", base::FEATURE_ENABLED_BY_DEFAULT
+};
+
+} // namespace features
 
 WebNotificationDelegate::WebNotificationDelegate(
     NotificationCommon::Type notification_type,
@@ -39,16 +55,52 @@
 }
 
 bool WebNotificationDelegate::ShouldDisplaySettingsButton() {
-  return notification_type_ != NotificationCommon::EXTENSION;
+  return true;
 }
 
 bool WebNotificationDelegate::ShouldDisplayOverFullscreen() const {
-  NotificationDisplayService* display_service =
-      NotificationDisplayServiceFactory::GetForProfile(profile_);
+#if !defined(OS_ANDROID)
+  // Check to see if this notification comes from a webpage that is displaying
+  // fullscreen content.
+  for (auto* browser : *BrowserList::GetInstance()) {
+    // Only consider the browsers for the profile that created the notification
+    if (browser->profile() != profile_)
+      continue;
 
-  return display_service->ShouldDisplayOverFullscreen(origin_,
-                                                      notification_type_);
+    const content::WebContents* active_contents =
+        browser->tab_strip_model()->GetActiveWebContents();
+    if (!active_contents)
+      continue;
+
+    // Check to see if
+    //  (a) the active tab in the browser shares its origin with the
+    //      notification.
+    //  (b) the browser is fullscreen
+    //  (c) the browser has focus.
+    if (active_contents->GetURL().GetOrigin() == origin_ &&
+        browser->exclusive_access_manager()->context()->IsFullscreen() &&
+        browser->window()->IsActive()) {
+      bool enabled = base::FeatureList::IsEnabled(
+          features::kAllowFullscreenWebNotificationsFeature);
+      if (enabled) {
+        UMA_HISTOGRAM_ENUMERATION("Notifications.Display_Fullscreen.Shown",
+                                  NotifierId::WEB_PAGE,
+                                  NotifierId::SIZE);
+      } else {
+        UMA_HISTOGRAM_ENUMERATION(
+            "Notifications.Display_Fullscreen.Suppressed",
+            NotifierId::WEB_PAGE,
+            NotifierId::SIZE);
+      }
+      return enabled;
+    }
+  }
+#endif
+
+  return false;
 }
+
+void WebNotificationDelegate::Display() {}
 
 void WebNotificationDelegate::Close(bool by_user) {
   auto* display_service =