[Presentation API] Additional plumbing for PresentationServiceImpl.

content/common/presentation/presentation_service.mojom

Index: content/common/presentation/presentation_service.mojom
diff --git a/content/common/presentation/presentation_service.mojom b/content/common/presentation/presentation_service.mojom
index d1e4b07909b59f888cd7f09433da54fcdb0742c0..a41bb8bd5e69c25855af159d91f31caa3daa4e36 100644
--- a/content/common/presentation/presentation_service.mojom
+++ b/content/common/presentation/presentation_service.mojom
@@ -7,7 +7,6 @@ module presentation;
 import "presentation_session.mojom";
 
 struct PresentationSessionInfo {
-    PresentationSession session;
     string url;
     string id;
 };
@@ -20,7 +19,7 @@ enum PresentationErrorType {
 };
 
 struct PresentationError {
-    PresentationErrorType errorType;
+    PresentationErrorType error_type;
     string message;
 };
 
@@ -39,6 +38,10 @@ interface PresentationService {
     // |availablechange| event.
     OnScreenAvailabilityListenerRemoved();
 
+    // Sets the default presentation URL for the frame.
+    // If parameter is an empty string, clears the default presentation URL.
+    SetDefaultPresentationUrl(string default_presentation_url);
+
     // Called when startSession() is called by the frame. The result callback
     // will return a non-null and valid PresentationSessionInfo if starting the
     // session succeeded, or null with a PresentationError if starting the
@@ -58,4 +61,4 @@ interface PresentationService {
     // silently and without user action.
     JoinSession(string presentation_url, string? presentation_id)
         => (PresentationSessionInfo? sessionInfo, PresentationError? error);
-};
+};