[Media Router] Implement an internal Media Routes observer.

chrome/browser/media/router/media_router_base.h

Index: chrome/browser/media/router/media_router_base.h
diff --git a/chrome/browser/media/router/media_router_base.h b/chrome/browser/media/router/media_router_base.h
index e95fa177cdab3b2951b6f97b4bfdfa6375e82dd7..bb2697b8b38056c366091ac35775293b74fae424 100644
--- a/chrome/browser/media/router/media_router_base.h
+++ b/chrome/browser/media/router/media_router_base.h
@@ -6,21 +6,21 @@
 #define CHROME_BROWSER_MEDIA_ROUTER_MEDIA_ROUTER_BASE_H_
 
 #include <set>
+#include <vector>
 
 #include "base/callback_list.h"
 #include "base/containers/scoped_ptr_hash_map.h"
 #include "base/gtest_prod_util.h"
 #include "base/macros.h"
 #include "base/threading/thread_checker.h"
+#include "chrome/browser/media/router/media_route.h"
 #include "chrome/browser/media/router/media_router.h"
-
-class Profile;
+#include "chrome/browser/media/router/media_routes_observer.h"
 
 namespace media_router {
 
 class MediaRouterBase : public MediaRouter {
  public:
-  MediaRouterBase();
   ~MediaRouterBase() override;
 
   std::unique_ptr<PresentationConnectionStateSubscription>
@@ -39,6 +39,8 @@ class MediaRouterBase : public MediaRouter {
   FRIEND_TEST_ALL_PREFIXES(MediaRouterMojoImplTest,
                            PresentationConnectionStateChangedCallbackRemoved);
 
+  MediaRouterBase();
+
   // Generates a unique presentation id. Shared between Android and desktop.
   static std::string CreatePresentationId();
 
@@ -50,13 +52,12 @@ class MediaRouterBase : public MediaRouter {
       content::PresentationConnectionCloseReason reason,
       const std::string& message);
 
-  // Called when off the record route |route_id| has been created.
-  void OnOffTheRecordRouteCreated(const MediaRoute::Id& route_id);
-  // Called when route |route_id| has been terminated.
-  void OnRouteTerminated(const MediaRoute::Id& route_id);
+  // Returns true when there is at least one MediaRoute with is_local = true.
+  bool HasLocalRoute() const;
 
   using PresentationConnectionStateChangedCallbacks = base::CallbackList<void(
       const content::PresentationConnectionStateChangeInfo&)>;
+
   base::ScopedPtrHashMap<
       MediaRoute::Id,
       std::unique_ptr<PresentationConnectionStateChangedCallbacks>>
@@ -65,13 +66,41 @@ class MediaRouterBase : public MediaRouter {
   base::ThreadChecker thread_checker_;
 
  private:
+  friend class MediaRouterFactory;
+  friend class MediaRouterMojoTest;
+
+  // Must be called before invoking any other method.
+  void Initialize();
+
+  // A MediaRoutesObserver that maintains state about the current set of media
+  // routes.
+  class InternalMediaRoutesObserver : public MediaRoutesObserver {
+   public:
+    explicit InternalMediaRoutesObserver(MediaRouter* router);
+    ~InternalMediaRoutesObserver() override;
+
+    // MediaRoutesObserver
+    void OnRoutesUpdated(
+        const std::vector<MediaRoute>& routes,
+        const std::vector<MediaRoute::Id>& joinable_route_ids) override;
+
+    bool has_local_route;

[imcheng, 2016/04/25 18:59:54]

nit: prefer moving member variables to private and exposing getters.

[mark a. foltz, 2016/04/26 21:11:10]

This entire class is a private implementation detail of MediaRouterBase, I don't
think accessors add much value vs. code bloat here.

I did find the following advice and moved this to the implementation file.

http://www.chromium.org/developers/coding-style/cpp-dos-and-donts#TOC-Move-in...

+    std::vector<MediaRoute::Id> off_the_record_route_ids;
+
+   private:
+    DISALLOW_COPY_AND_ASSIGN(InternalMediaRoutesObserver);
+  };
+
   // Called when a PresentationConnectionStateChangedCallback associated with
   // |route_id| is removed from |presentation_connection_state_callbacks_|.
   void OnPresentationConnectionStateCallbackRemoved(
       const MediaRoute::Id& route_id);
 
-  // Ids of current off the record media routes.
-  std::set<MediaRoute::Id> off_the_record_route_ids_;
+  // KeyedService
+  void Shutdown() override;
+
+  std::unique_ptr<InternalMediaRoutesObserver> internal_routes_observer_;
+  bool initialized_;
 
   DISALLOW_COPY_AND_ASSIGN(MediaRouterBase);
 };