[Presentation API] Additional plumbing for PresentationServiceImpl.

content/browser/presentation/presentation_service_impl.h

Index: content/browser/presentation/presentation_service_impl.h
diff --git a/content/browser/presentation/presentation_service_impl.h b/content/browser/presentation/presentation_service_impl.h
index 65e729f49bd85d0c73f5ba844c23837237dedf05..d86474fa6490350480ab6809e6536b13fa4ba2a5 100644
--- a/content/browser/presentation/presentation_service_impl.h
+++ b/content/browser/presentation/presentation_service_impl.h
@@ -11,6 +11,7 @@
 #include "base/gtest_prod_util.h"
 #include "base/macros.h"
 #include "base/memory/linked_ptr.h"
+#include "base/memory/weak_ptr.h"
 #include "content/common/content_export.h"
 #include "content/common/presentation/presentation_service.mojom.h"
 #include "content/common/presentation/presentation_session.mojom.h"
@@ -56,7 +57,7 @@ class CONTENT_EXPORT PresentationServiceImpl
           presentation::PresentationErrorPtr)>;
 
   friend class PresentationServiceImplTest;
-  FRIEND_TEST_ALL_PREFIXES(PresentationServiceImplTest, RemoveAllListeners);
+  FRIEND_TEST_ALL_PREFIXES(PresentationServiceImplTest, Reset);
   FRIEND_TEST_ALL_PREFIXES(PresentationServiceImplTest,
       DidNavigateThisFrame);
   FRIEND_TEST_ALL_PREFIXES(PresentationServiceImplTest,
@@ -65,6 +66,12 @@ class CONTENT_EXPORT PresentationServiceImpl
       ThisRenderFrameDeleted);
   FRIEND_TEST_ALL_PREFIXES(PresentationServiceImplTest,
       NotThisRenderFrameDeleted);
+  FRIEND_TEST_ALL_PREFIXES(PresentationServiceImplTest,
+      SetDefaultPresentationUrl);
+  FRIEND_TEST_ALL_PREFIXES(PresentationServiceImplTest,
+      SetSameDefaultPresentationUrl);
+  FRIEND_TEST_ALL_PREFIXES(PresentationServiceImplTest,
+      ClearDefaultPresentationUrl);
 
   // |render_frame_host|: The RFH this instance is associated with.
   // |web_contents|: The WebContents to observe.
@@ -88,6 +95,8 @@ class CONTENT_EXPORT PresentationServiceImpl
       const mojo::String& presentation_url,
       const mojo::String& presentation_id,
       const NewSessionMojoCallback& callback) override;
+  void SetDefaultPresentationUrl(
+      const mojo::String& presentation_url) override;
 
   // mojo::InterfaceImpl override.
   // Note that this is called when the RenderFrameHost is deleted.
@@ -103,9 +112,18 @@ class CONTENT_EXPORT PresentationServiceImpl
   // PresentationServiceDelegate::Observer
   void OnDelegateDestroyed() override;
 
-  // Removes all listeners on this instance and informs the
-  // PresentationServiceDelegate of such.
-  void RemoveAllListeners();
+  // Sets |default_presentation_url_| to |presentation_url| and informs the
+  // delegate of such.
+  void DoSetDefaultPresentationUrl(const std::string& presentation_url);
+
+  // Removes all listeners and resets default presentation URL on this instance
+  // and informs the PresentationServiceDelegate of such.
+  void Reset();
+
+  // Callbacks from the embedder as a result of StartSession/JoinSession.
+  void OnStartOrJoinSessionSucceeded(
+      const PresentationSessionInfo& session_info);
+  void OnStartOrJoinSessionError(const PresentationError& error);
 
   RenderFrameHost* render_frame_host_;
   PresentationServiceDelegate* delegate_;
@@ -144,6 +162,11 @@ class CONTENT_EXPORT PresentationServiceImpl
     // |available|: New screen availability for the presentation URL.
     void OnScreenAvailabilityChanged(bool available) override;
 
+    // Gets the callback as a raw pointer.
+    ScreenAvailabilityMojoCallback* callback() const {
+      return callback_ptr_.get();
+    }
+
    private:
     std::string presentation_url_;
     scoped_ptr<ScreenAvailabilityMojoCallback> callback_ptr_;
@@ -156,6 +179,16 @@ class CONTENT_EXPORT PresentationServiceImpl
 
   std::string default_presentation_url_;
 
+  // This is set when there is a StartSession/JoinSession in progress.
+  // Additional StartSession/JoinSession calls are ignored while this is
+  // set.

[mark a. foltz, 2015/03/11 01:08:19]

Normally I wouldn't expect overlapping calls, but not always.  What is the
behavior the client will see in this scenario:

Promise p1 = joinSession(URL).then(...)
Promise p2 = startSession(URL)

Will p2 never resolve, or reject...?

[imcheng, 2015/03/12 20:03:41]

For JoinSession, we should be able to let them overlap. PSImpl would just need
to know how to match up the callback with each JoinSession request. We can
choose to not allow overlapping JoinSession for the same presentation id (i.e.
if PSImpl matches callbacks by presentation ID)

For StartSession, since it brings up a dialog, it does not make sense to have
overlapping calls. We can queue up excess StartSession calls if there's one in
progress. Once the first one resolves/rejects, we can process the next request
in the queue and bring up the dialog.

I can make this change in next patch set if there are no objections.

+  // When embedder returns with a result, this callback will be invoked and then
+  // reset.
+  scoped_ptr<NewSessionMojoCallback> start_or_join_session_cb_;
+
+  // NOTE: Weak pointers must be invalidated before all other member variables.
+  base::WeakPtrFactory<PresentationServiceImpl> weak_factory_;
+
   DISALLOW_COPY_AND_ASSIGN(PresentationServiceImpl);
 };