[PresentationAPI] Implementing send() from WebPresentationClient to the PresentationService.

content/browser/presentation/presentation_service_impl.h

Index: content/browser/presentation/presentation_service_impl.h
diff --git a/content/browser/presentation/presentation_service_impl.h b/content/browser/presentation/presentation_service_impl.h
index 21de733b7b0cab9558f7b9feff54661c7d687961..3515fd4540ad0eb08fa82827d73af191dd384bb0 100644
--- a/content/browser/presentation/presentation_service_impl.h
+++ b/content/browser/presentation/presentation_service_impl.h
@@ -64,6 +64,7 @@ class CONTENT_EXPORT PresentationServiceImpl
   using SessionStateCallback =
       mojo::Callback<void(presentation::PresentationSessionInfoPtr,
           presentation::PresentationSessionState)>;
+  using SendMessageMojoCallback = mojo::Callback<void(bool)>;
 
   // A helper data class used by PresentationServiceImpl to do bookkeeping
   // of currently registered screen availability listeners.
@@ -202,6 +203,9 @@ class CONTENT_EXPORT PresentationServiceImpl
       const mojo::String& presentation_url,
       const mojo::String& presentation_id,
       const NewSessionMojoCallback& callback) override;
+  void SendMessage(
+      presentation::SessionMessagePtr message_request,
+      const SendMessageMojoCallback& callback) override;
   void CloseSession(
       const mojo::String& presentation_url,
       const mojo::String& presentation_id) override;
@@ -245,7 +249,7 @@ class CONTENT_EXPORT PresentationServiceImpl
   // and informs the PresentationServiceDelegate of such.
   void Reset();
 
-  // These two functions are bound as base::Callbacks and passed to
+  // These functions are bound as base::Callbacks and passed to
   // embedder's implementation of PresentationServiceDelegate for later
   // invocation.
   void OnStartOrJoinSessionSucceeded(
@@ -256,6 +260,7 @@ class CONTENT_EXPORT PresentationServiceImpl
       bool is_start_session,
       int request_session_id,
       const PresentationError& error);
+  void OnSendMessageCallback();
 
   // Requests delegate to start a session.
   void DoStartSession(
@@ -321,6 +326,9 @@ class CONTENT_EXPORT PresentationServiceImpl
   // NOTE: Weak pointers must be invalidated before all other member variables.
   base::WeakPtrFactory<PresentationServiceImpl> weak_factory_;
 
+  // There could be one send message request at a time.
+  scoped_ptr<SendMessageMojoCallback> send_message_cb_ptr_;
+
   DISALLOW_COPY_AND_ASSIGN(PresentationServiceImpl);
 };