[chrome.displaySource] Simplify session error types

This patch reduces amount of possible session error types and
makes them more generic (less WiFi Display oriented).

BUG=242107

Review URL: https://codereview.chromium.org/1689913003

Cr-Commit-Position: refs/heads/master@{#375437}

2 files changed, 11 insertions, 16 deletions

diff --git a/extensions/common/api/display_source.idl b/extensions/common/api/display_source.idl
index 83cfa0d..00434a6 100644
--- a/extensions/common/api/display_source.idl
+++ b/extensions/common/api/display_source.idl
@@ -6,31 +6,22 @@
 // session using WebMediaStreamTrack as sources.
 namespace displaySource {
   enum ErrorType {
-    // Cannot create media pipeline from the given media stream which could be
-    // appropriate for a Display session (e.g., necessary codecs are missing
-    // on the platform).
-    create_media_pipeline_error,
-
     // A new Display session cannot be started before the existing one is
     // terminated.
-    exceeded_session_limit_error,
+    session_limit_error,
 
-    // Could not establish connection to the sink.
-    establish_connection_error,
+    // The connection with sink cannot be established or has dropped
+    // unexpectedly.
+    connection_error,
 
     // The capabilities of this Display Source and the connected  
     // sink do not fit (e.g. the sink cannot play the media content of
     // the formats given by the source).
     capabilities_negotiation_error,
 
-    // There was an error while packetizing and sending the media content.
-    media_send_error,
-
-    // The TCP connection with sink has dropped unexpectedly.
-    connection_error,
-
-    // An unexpected message has arrived from the sink.
-    unexpected_message_error,
+    // There was an error in media pipeline: while encoding, packetizing or
+    // sending the media content.
+    media_pipeline_error,
 
     // The sink became unresponsive.
     timeout_error,
diff --git a/extensions/common/mojo/wifi_display_session_service.mojom b/extensions/common/mojo/wifi_display_session_service.mojom
index 637a1f0..025ed7f 100644
--- a/extensions/common/mojo/wifi_display_session_service.mojom
+++ b/extensions/common/mojo/wifi_display_session_service.mojom
@@ -10,6 +10,8 @@ interface WiFiDisplaySessionService {
   SetClient(WiFiDisplaySessionServiceClient client);
 
   // Requires connection to a sink using the given authentication information.
+  // Note: 'auth_method' values must correspond to 'enum AuthenticationMethod'
+  // from display_source.idl
   Connect(int32 sink_id, int32 auth_method, string auth_data);
 
   // Drops the established connection to the connected sink.
@@ -27,6 +29,8 @@ interface WiFiDisplaySessionServiceClient {
   OnTerminated();
 
   // Notification of an error occurred during the session.
+  // Note: 'type' values must correspond to 'enum ErrorType'
+  // from display_source.idl
   OnError(int32 type, string description);
 
   // Invoked to transmit a controlling message from