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 5c1a2d37c8ab591dec67de8ce80dd4456aa69c8c..e554592ef22959a37ff00aabe1fddff63511befa 100644
--- a/content/public/browser/content_browser_client.cc
+++ b/content/public/browser/content_browser_client.cc
@@ -211,12 +211,9 @@ 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(