[Presentation API] Adds close method to Presentation session.

Source/modules/presentation/PresentationSession.h

Index: Source/modules/presentation/PresentationSession.h
diff --git a/Source/modules/presentation/PresentationSession.h b/Source/modules/presentation/PresentationSession.h
index 9a28e6cf617ee0d6c7689bf308f0fd49abd7c434..52d21eeae3b093799e18e0812ece9d26de6b6f1f 100644
--- a/Source/modules/presentation/PresentationSession.h
+++ b/Source/modules/presentation/PresentationSession.h
@@ -13,6 +13,7 @@
 namespace blink {
 
 class Presentation;
+class PresentationController;
 class WebPresentationSessionClient;
 class WebString;
 
@@ -45,6 +46,10 @@ public:
 private:
     PresentationSession(LocalFrame*, const WebString& id);
 
+    // Returns the |PresentationController| object associated with the frame |Presentation| corresponds to.

[whywhat, 2015/03/17 23:35:19]

nit: Although Blink doesn't yet have line length limit, it doesn't forbid to
limit comments to 80 chars (unlike method prototypes, for example). I think
keeping this comment in 80 chars would make the reviews/reading the code
relatively easier.

[haibinlu, 2015/03/18 00:58:23]

Done.

+    // Can return |nullptr| if the frame is detached from the document.
+    PresentationController* presentationController();
+
     String m_id;
     AtomicString m_state;
 };