Cleanup TrayCast with media-router only support in mind.

ash/common/cast_config_delegate.h

Index: ash/common/cast_config_delegate.h
diff --git a/ash/common/cast_config_delegate.h b/ash/common/cast_config_delegate.h
index 2f3fec209ecdae2cf06318887cb222894ec38b08..63a580b5720bf18c452067f0644f8cc5cb0446d0 100644
--- a/ash/common/cast_config_delegate.h
+++ b/ash/common/cast_config_delegate.h
@@ -26,22 +26,11 @@ class CastConfigDelegate {
 
     std::string id;
     base::string16 name;
+    base::string16 domain;
   };
 
   struct ASH_EXPORT Route {
-    // The tab identifier that we are casting. These are the special tab values
-    // taken from the chromecast extension itself. If an actual tab is being
-    // casted, then the TabId will be >= 0.
-    enum TabId {
-      EXTENSION = -1,
-      DESKTOP = -2,
-      DISCOVERED_ACTIVITY = -3,
-      EXTERNAL_EXTENSION_CLIENT = -4,
-
-      // Not in the extension. Used when the extension does not give us a tabId
-      // (ie, the cast is running from another device).
-      UNKNOWN = -5
-    };
+    enum class ContentSource { UNKNOWN, TAB, DESKTOP };
 
     Route();
     ~Route();
@@ -49,16 +38,12 @@ class CastConfigDelegate {
     std::string id;
     base::string16 title;
 
-    // Is the route source this computer? ie, are we mirroring the display?
+    // Is the activity originating from this computer?
     bool is_local_source = false;
 
-    // The id for the tab we are casting. Could be one of the TabId values,
-    // or a value >= 0 that represents that tab index of the tab we are
-    // casting. We default to casting the desktop, as a tab may not
-    // necessarily exist.
-    // TODO(jdufault): Remove tab_id once the CastConfigDelegateChromeos is
-    // gone. See crbug.com/551132.
-    int tab_id = TabId::DESKTOP;
+    // What is source of the content? For example, we could be DIAL casting a
+    // tab or mirroring the entire desktop.
+    ContentSource content_source = ContentSource::UNKNOWN;
   };
 
   struct ASH_EXPORT SinkAndRoute {
@@ -89,12 +74,11 @@ class CastConfigDelegate {
   // registered observers will get called.
   virtual void RequestDeviceRefresh() = 0;
 
-  // Cast to a sink specified by |sink_id|.
-  virtual void CastToSink(const std::string& sink_id) = 0;
+  // Initiate a casting session to |sink|.
+  virtual void CastToSink(const Sink& sink) = 0;
 
-  // Stop an ongoing cast (this should be a user initiated stop). |route_id|
-  // is the identifier of the sink/route that should be stopped.
-  virtual void StopCasting(const std::string& route_id) = 0;
+  // A user-initiated request to stop the given cast session.
+  virtual void StopCasting(const Route& route) = 0;
 
   // Add or remove an observer.
   virtual void AddObserver(Observer* observer) = 0;