[Media Router] Make per-hostname cast mode selections persist

chrome/browser/ui/webui/media_router/media_router_ui.h

Index: chrome/browser/ui/webui/media_router/media_router_ui.h
diff --git a/chrome/browser/ui/webui/media_router/media_router_ui.h b/chrome/browser/ui/webui/media_router/media_router_ui.h
index dd329318b9f080aece510d8be5b168f4ab7758cc..8ef7eff6d1f315ed352d472657ea769d78582857 100644
--- a/chrome/browser/ui/webui/media_router/media_router_ui.h
+++ b/chrome/browser/ui/webui/media_router/media_router_ui.h
@@ -128,6 +128,14 @@ class MediaRouterUI : public ConstrainedWebDialogUI,
                                  const std::string& domain,
                                  MediaCastMode cast_mode);
 
+  // Returns the cast mode that user has last chosen for the current hostname.
+  // If user hasn't chosen any, this returns MediaCastMode::DEFAULT.

[imcheng, 2016/11/14 19:32:27]

MediaCastMode::DEFAULT is a valid value that represents presentation. Are we
sure we want to use it if the user did not choose a cast mode before?

[takumif, 2016/11/16 01:34:27]

Changing this to
bool UserSelectedTabMirroringForCurrentHost().

+  MediaCastMode GetCastModeSelectionForCurrentHost() const;
+
+  // Records the cast mode selection for the current hostname, unless the cast
+  // mode is MediaCastMode::DESKTOP_MIRROR.
+  void RecordCastModeSelection(MediaCastMode cast_mode);
+
   // Returns the hostname of the default source's parent frame URL.
   std::string GetPresentationRequestSourceName() const;
   std::string GetTruncatedPresentationRequestSourceName() const;
@@ -276,6 +284,10 @@ class MediaRouterUI : public ConstrainedWebDialogUI,
   // Otherwise returns an empty GURL.
   GURL GetFrameURL() const;
 
+  // Returns the hostname (e.g. "cs.chromium.org") for |initiator_|, or an empty
+  // string if |initiator_| is not set.
+  std::string GetInitiatorHostname() const;
+
   // Owned by the |web_ui| passed in the ctor, and guaranteed to be deleted
   // only after it has deleted |this|.
   MediaRouterWebUIMessageHandler* handler_;