Presentation API: ignore presentation id passed to startSession().

content/renderer/presentation/presentation_dispatcher.h

Index: content/renderer/presentation/presentation_dispatcher.h
diff --git a/content/renderer/presentation/presentation_dispatcher.h b/content/renderer/presentation/presentation_dispatcher.h
index 4642a644ba19899a626ce3a0db05f8e070d277cf..6aedd043b5563955b4efa6a7b5d16f23b8b4cadb 100644
--- a/content/renderer/presentation/presentation_dispatcher.h
+++ b/content/renderer/presentation/presentation_dispatcher.h
@@ -35,6 +35,10 @@ class CONTENT_EXPORT PresentationDispatcher
   virtual void updateAvailableChangeWatched(bool watched);
   virtual void startSession(
       const blink::WebString& presentationUrl,
+      blink::WebPresentationSessionClientCallbacks* callback);
+  // TODO(mlamouri): remove this one when the one above is used by Blink.
+  virtual void startSession(
+      const blink::WebString& presentationUrl,
       const blink::WebString& presentationId,
       blink::WebPresentationSessionClientCallbacks* callback);
   virtual void joinSession(