Start pulling away notification logic from ChromeContentBrowserClient.

content/public/browser/content_browser_client.cc

Index: content/public/browser/content_browser_client.cc
diff --git a/content/public/browser/content_browser_client.cc b/content/public/browser/content_browser_client.cc
index e32344940ef368946620a3856aceb1006f125c10..d8d21b334fdd9b362da79e1d2579de1201bb6a30 100644
--- a/content/public/browser/content_browser_client.cc
+++ b/content/public/browser/content_browser_client.cc
@@ -219,12 +219,9 @@ MediaObserver* ContentBrowserClient::GetMediaObserver() {
   return NULL;
 }
 
-blink::WebNotificationPermission
-ContentBrowserClient::CheckDesktopNotificationPermission(
-    const GURL& source_origin,
-    ResourceContext* context,
-    int render_process_id) {
-  return blink::WebNotificationPermissionDenied;
+PlatformNotificationService*
+ContentBrowserClient::GetPlatformNotificationService() {
+  return NULL;
 }
 
 void ContentBrowserClient::RequestPermission(