Add initial support for native Linux desktop notifications

chrome/browser/notifications/notification_display_service_factory.cc

Index: chrome/browser/notifications/notification_display_service_factory.cc
diff --git a/chrome/browser/notifications/notification_display_service_factory.cc b/chrome/browser/notifications/notification_display_service_factory.cc
index 8b40bcdab31544c9e5c7c2a0f2df89c79634622f..a707dff78ca401ea1df79fad87aa5f91f23f0b15 100644
--- a/chrome/browser/notifications/notification_display_service_factory.cc
+++ b/chrome/browser/notifications/notification_display_service_factory.cc
@@ -14,7 +14,8 @@
 #include "chrome/common/chrome_features.h"
 #include "components/keyed_service/content/browser_context_dependency_manager.h"
 
-#if defined(OS_ANDROID) || defined(OS_MACOSX)
+#if defined(OS_ANDROID) || defined(OS_MACOSX) || \
+    (defined(OS_LINUX) && !defined(OS_CHROMEOS))

[Lei Zhang, 2017/04/04 07:47:21]

To make this even longer, do we need to gate this on defined(USE_GIO) as well,
in case someone building Chromium decides to set use_gio = false?

[Peter Beverloo, 2017/04/04 13:34:46]

It probably makes sense to use a BUILDFLAG for this so that we can define the
logic once in GN.

[Tom (Use chromium acct), 2017/04/04 21:47:10]

Added the BUILDFLAG and made the condition depend on use_gio as well.

 #include "chrome/browser/notifications/native_notification_display_service.h"
 #endif
 
@@ -48,8 +49,9 @@ KeyedService* NotificationDisplayServiceFactory::BuildServiceInstanceFor(
   return new NativeNotificationDisplayService(
       Profile::FromBrowserContext(context),
       g_browser_process->notification_platform_bridge());
-#elif defined(OS_MACOSX)
-  if (base::FeatureList::IsEnabled(features::kNativeNotifications)) {
+#elif defined(OS_MACOSX) || (defined(OS_LINUX) && !defined(OS_CHROMEOS))
+  if (base::FeatureList::IsEnabled(features::kNativeNotifications) &&
+      g_browser_process->notification_platform_bridge()) {
     return new NativeNotificationDisplayService(
         Profile::FromBrowserContext(context),
         g_browser_process->notification_platform_bridge());