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

content/public/browser/presentation_service_delegate.h

Index: content/public/browser/presentation_service_delegate.h
diff --git a/content/public/browser/presentation_service_delegate.h b/content/public/browser/presentation_service_delegate.h
index 817cd282a8f246eac8ac6a2e7bda0ccba940f5f7..9950de1e4e95c21feaeefe0a30ec517c87b058cb 100644
--- a/content/public/browser/presentation_service_delegate.h
+++ b/content/public/browser/presentation_service_delegate.h
@@ -7,6 +7,7 @@
 
 #include "base/callback.h"
 #include "content/common/content_export.h"
+//#include "content/common/presentation/presentation_message.h"
 #include "content/public/browser/presentation_session.h"
 
 namespace content {
@@ -31,6 +32,7 @@ class CONTENT_EXPORT PresentationServiceDelegate {
       base::Callback<void(const PresentationSessionInfo&)>;
   using PresentationSessionErrorCallback =
       base::Callback<void(const PresentationError&)>;
+  using SendMessageCallback = base::Callback<void()>;
 
   virtual ~PresentationServiceDelegate() {}
 
@@ -115,6 +117,17 @@ class CONTENT_EXPORT PresentationServiceDelegate {
       const std::string& presentation_id,
       const PresentationSessionSuccessCallback& success_cb,
       const PresentationSessionErrorCallback& error_cb) = 0;
+
+  // Sends a message (string or binary data) to a presentation session.
+  // |render_process_id|, |render_frame_id|: ID of originating frame.
+  // |message_request|: Contains Presentation URL, ID and message to be sent.
+  // TODO(s.singapati): Need to move presentation_message.h
+  /*
+  virtual void SendMessage(
+      int render_process_id,
+      int render_frame_id,
+      MessageRequest* message_request) = 0;
+      */
 };
 
 }  // namespace content