[Media Router] Add a presentation id to MediaRoute mapping in the MR

chrome/browser/media/router/media_router_base.cc

Index: chrome/browser/media/router/media_router_base.cc
diff --git a/chrome/browser/media/router/media_router_base.cc b/chrome/browser/media/router/media_router_base.cc
index 923afc4efc79b6e37ec7dc9f865c8d1f5b3f6c2b..489d6f00ce8198937a3ec93cf444bef6b03b3c3c 100644
--- a/chrome/browser/media/router/media_router_base.cc
+++ b/chrome/browser/media/router/media_router_base.cc
@@ -4,6 +4,8 @@
 
 #include "chrome/browser/media/router/media_router_base.h"
 
+#include <map>
+
 #include "base/bind.h"
 #include "base/guid.h"
 #include "base/memory/ptr_util.h"
@@ -38,9 +40,28 @@ class MediaRouterBase::InternalMediaRoutesObserver
     }
   }
 
+  void RegisterPresentationRoute(const std::string& presentation_id,
+                                 const MediaRoute& route) {
+    presentation_id_route.insert(std::make_pair(presentation_id, route));
+  }
+
+  void UnregisterPresentationRoute(const std::string& presentation_id) {
+    presentation_id_route.erase(presentation_id);

[imcheng, 2017/03/08 20:06:35]

If a MediaRoute was removed by the MRP, how is the associated entry removed from
the map?

[mark a. foltz, 2017/03/08 22:01:47]

One solution would be for each update sent to the internal routes observer would
check if a newly-removed route was in the map, and remove it.

If we went with keeping the id in the route, then you would only need to have
add the Get() method to iterate through the routes in the internal observer and
find the matching route.

[zhaobin, 2017/03/09 00:34:27]

Done.

+  }
+
+  const MediaRoute* GetPresentationRoute(
+      const std::string& presentation_id) const {
+    auto it = presentation_id_route.find(presentation_id);
+    if (it == presentation_id_route.end())
+      return nullptr;
+
+    return &it->second;
+  }
+
   bool has_route;
   std::vector<MediaRoute> current_routes;
   std::vector<MediaRoute::Id> incognito_route_ids;
+  std::map<std::string, MediaRoute> presentation_id_route;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(InternalMediaRoutesObserver);
@@ -76,6 +97,25 @@ std::vector<MediaRoute> MediaRouterBase::GetCurrentRoutes() const {
   return internal_routes_observer_->current_routes;
 }
 
+void MediaRouterBase::RegisterPresentationRoute(
+    const std::string& presentation_id,
+    const MediaRoute& route) {
+  DCHECK(internal_routes_observer_);
+  internal_routes_observer_->RegisterPresentationRoute(presentation_id, route);
+}
+
+void MediaRouterBase::UnregisterPresentationRoute(
+    const std::string& presentation_id) {
+  DCHECK(internal_routes_observer_);
+  internal_routes_observer_->UnregisterPresentationRoute(presentation_id);
+}
+
+const MediaRoute* MediaRouterBase::GetPresentationRoute(
+    const std::string& presentation_id) const {
+  DCHECK(internal_routes_observer_);
+  return internal_routes_observer_->GetPresentationRoute(presentation_id);
+}
+
 MediaRouterBase::MediaRouterBase() : initialized_(false) {}
 
 // static