Include a deprecation warning when people only use "gcm_user_visible_only".

content/renderer/push_messaging/push_messaging_dispatcher.cc

Index: content/renderer/push_messaging/push_messaging_dispatcher.cc
diff --git a/content/renderer/push_messaging/push_messaging_dispatcher.cc b/content/renderer/push_messaging/push_messaging_dispatcher.cc
index e3f838a1af4d3d55f6a211b989542cd4b5a2f677..87d542898db980ed76fd413d0d1476d8d504b64a 100644
--- a/content/renderer/push_messaging/push_messaging_dispatcher.cc
+++ b/content/renderer/push_messaging/push_messaging_dispatcher.cc
@@ -15,12 +15,19 @@
 #include "third_party/WebKit/public/platform/modules/push_messaging/WebPushError.h"
 #include "third_party/WebKit/public/platform/modules/push_messaging/WebPushSubscription.h"
 #include "third_party/WebKit/public/platform/modules/push_messaging/WebPushSubscriptionOptions.h"
+#include "third_party/WebKit/public/web/WebConsoleMessage.h"
+#include "third_party/WebKit/public/web/WebLocalFrame.h"
 #include "url/gurl.h"
 
 using blink::WebString;
 
 namespace content {
 
+const char kManifestDeprecationWarning[] =

[johnme, 2015/05/20 14:05:41]

Move to anonymous namespace?

[Peter Beverloo, 2015/05/20 14:15:13]

No, constants are internally linked by default so it wouldn't make a difference.

+    "The 'gcm_user_visible_only' manifest key is deprecated and will be "
+    "removed in Chrome 45, around August 2015. Use PushSubscriptionOptions "

[johnme, 2015/05/20 14:05:41]

Nit: How about "Call pushManager.subscribe({userVisibleOnly:true}) instead (see
https://w3c.github.io/push-api/#pushsubscriptionoptions-dictionary)." instead of
the last sentence.

[Peter Beverloo, 2015/05/20 14:15:14]

Changed..

+    "when subscribing for push instead.";
+
 PushMessagingDispatcher::PushMessagingDispatcher(RenderFrame* render_frame)
     : RenderFrameObserver(render_frame) {
 }
@@ -74,8 +81,17 @@ void PushMessagingDispatcher::DoSubscribe(
     return;
   }
 
-  // TODO(peter): Display a deprecation warning if gcm_user_visible_only is
-  // set to true. See https://crbug.com/471534
+  // Support for the "gcm_user_visible_only" Manifest key has been deprecated
+  // in favor of the userVisibleOnly subscription option, and will be removed
+  // in a future Chrome release. Inform developers of this deprecation.
+  if (manifest.gcm_user_visible_only && !options.userVisibleOnly) {
+    blink::WebConsoleMessage message(
+        blink::WebConsoleMessage::LevelWarning,
+        blink::WebString::fromUTF8(kManifestDeprecationWarning));
+
+    render_frame()->GetWebFrame()->addMessageToConsole(message);

[johnme, 2015/05/20 14:05:41]

Ideally we'd log no more than once per page load; but I guess pages are unlikely
to subscribe many times per page load, so it's probably fine.

[Peter Beverloo, 2015/05/20 14:15:13]

Acknowledged.

+  }
+
   const bool user_visible = manifest.gcm_user_visible_only ||
                             options.userVisibleOnly;