[Presentation API] Handle multiple Presentation URLs in PresentationRequest::getAvailability()

content/renderer/presentation/presentation_dispatcher.h

Index: content/renderer/presentation/presentation_dispatcher.h
diff --git a/content/renderer/presentation/presentation_dispatcher.h b/content/renderer/presentation/presentation_dispatcher.h
index 0693f1363f1731366f0e61ec02b49fc63746b415..beac99f55c070d71db4aba6d42e1abff33697fec 100644
--- a/content/renderer/presentation/presentation_dispatcher.h
+++ b/content/renderer/presentation/presentation_dispatcher.h
@@ -47,6 +47,7 @@ class CONTENT_EXPORT PresentationDispatcher
   ~PresentationDispatcher() override;
 
  private:
+  friend class PresentationDispatcherTest;
   struct SendMessageRequest {
     SendMessageRequest(blink::mojom::PresentationSessionInfoPtr session_info,
                        blink::mojom::ConnectionMessagePtr message);
@@ -140,6 +141,8 @@ class CONTENT_EXPORT PresentationDispatcher
   void HandleSendMessageRequests(bool success);
 
   void ConnectToPresentationServiceIfNeeded();
+  void SetPresentationServiceForTest(
+      blink::mojom::PresentationServicePtr presentation_service);
 
   void UpdateListeningState();
 
@@ -160,6 +163,13 @@ class CONTENT_EXPORT PresentationDispatcher
     ACTIVE,
   };
 
+  enum class ScreenAvailability {
+    UNKNOWN,
+    AVAILABLE,
+    UNAVAILABLE,
+    UNSUPPORTED

[mark a. foltz, 2016/12/23 01:04:22]

I don't recall exactly why we have an API in the dispatcher to report that a
specific URL is not supported for screen availability monitoring.  I would
normally think this is a property of the entire browser (for example a setting
or low battery mode) but this does give the embedder maximum flexibility.

I'm not sure how we should report overall availability for a request when some
of the URLs are unsupported...  maybe handle this the same as UNKNOWN?

[zhaobin, 2016/12/29 18:48:38]

Done.

+  };
+
   using AvailabilityCallbacksMap =
       IDMap<std::unique_ptr<blink::WebPresentationAvailabilityCallbacks>>;
   using AvailabilityObserversSet =
@@ -167,24 +177,46 @@ class CONTENT_EXPORT PresentationDispatcher
 
   // Tracks status of presentation displays availability for |availability_url|.
   struct AvailabilityStatus {
-    explicit AvailabilityStatus(const GURL& availability_url);
+    explicit AvailabilityStatus(const std::vector<GURL>& availability_urls);
     ~AvailabilityStatus();
 
-    const GURL url;
-    bool last_known_availability;
-    ListeningState listening_state;
+    const std::vector<GURL> urls;
     AvailabilityCallbacksMap availability_callbacks;
     AvailabilityObserversSet availability_observers;
   };
 
   // Map of AvailabilityStatus for known URLs.
-  std::map<GURL, std::unique_ptr<AvailabilityStatus>>
+  std::map<std::vector<GURL>, std::unique_ptr<AvailabilityStatus>>

[mark a. foltz, 2016/12/23 01:04:22]

Is it okay to use a container as a map key? 

I usually think of availability as applying to a specific URL.

[zhaobin, 2016/12/29 18:48:38]

Code removed.

       availability_status_;
 
+  // Map of ScreenAvailability for known URL.
+  std::map<GURL, ScreenAvailability> screen_availability_;
+
+  // Map of ListeningState for known URL.
+  std::map<GURL, ListeningState> url_listening_state_;

[mark a. foltz, 2016/12/23 01:04:22]

Can we combine these with AvailabilityStatus?

[zhaobin, 2016/12/29 18:48:38]

Code removed.

+
   // Updates the listening state of availability for |status| and notifies the
   // client.
   void UpdateListeningState(AvailabilityStatus* status);
 
+  // Called when all urls in |status| reports ScreenAvailability::UNSUPPORTED.
+  void OnScreenAvailabilityNotSupported(AvailabilityStatus* status);
+
+  // Called when all urls in |status| reports their screen availability.
+  void OnScreenAvailabilityUpdated(AvailabilityStatus* status, bool available);
+
+  void OnScreenAvailabilityUpdated(const GURL& url, ScreenAvailability);
+
+  // Returns UNKNOWN if any url in |urls| has screen availability UNKNOWN.
+  // Returns AVAILABLE if at least one url in |urls| has screen availability
+  // AVAILABLE, and no url has screen availability UNKNOWN;
+  // Returns UNAVAILABLE is at least one url in |urls| has screen availability
+  // UNAVAILABLE, and no url has screen availability UNKNOWN or AVAILABLE;
+  // Returns UNSUPPORTED if all urls in |urls| have screen availability
+  // UNSUPPORTED.
+  PresentationDispatcher::ScreenAvailability GetRequestAvailability(
+      const std::vector<GURL>& urls);
+
   DISALLOW_COPY_AND_ASSIGN(PresentationDispatcher);
 };