[MediaRouter] Plumb PresentationConnectionClose from MR to Blink.

Added some follow up plumbing in Blink for close reason, as well as to
send the new event via a new method in PresentationConnection.

Added plumbing in PresentationDispatcher and PresentationServiceImpl.

Added a new class to hold the (state change, close) callbacks in
content public API which will be used by PresentationServiceImpl and
MR.

Changed existing MR API to take the new callbacks object.

Added new MediaRouterMojoImpl API to be notified of presentation
connection close.

Added plumbing in media_router_bindings.js

TODO: add tests

BUG=579360,574233,574234

Review URL: https://codereview.chromium.org/1701143002

Cr-Commit-Position: refs/heads/master@{#376935}

1 files changed, 17 insertions, 2 deletions

diff --git a/content/public/browser/presentation_service_delegate.h b/content/public/browser/presentation_service_delegate.h
index d3b92be..fdd25c3 100644
--- a/content/public/browser/presentation_service_delegate.h
+++ b/content/public/browser/presentation_service_delegate.h
@@ -23,8 +23,6 @@ using PresentationSessionStartedCallback =
     base::Callback<void(const PresentationSessionInfo&)>;
 using PresentationSessionErrorCallback =
     base::Callback<void(const PresentationError&)>;
-using PresentationConnectionStateChangedCallback =
-    base::Callback<void(PresentationConnectionState)>;
 
 // Param #0: a vector of messages that are received.
 // Param #1: tells the callback handler that it may reuse strings or buffers
@@ -32,6 +30,23 @@ using PresentationConnectionStateChangedCallback =
 using PresentationSessionMessageCallback = base::Callback<
     void(const ScopedVector<content::PresentationSessionMessage>&, bool)>;
 
+struct PresentationConnectionStateChangeInfo {
+  explicit PresentationConnectionStateChangeInfo(
+      PresentationConnectionState state)
+      : state(state),
+        close_reason(PRESENTATION_CONNECTION_CLOSE_REASON_CONNECTION_ERROR) {}
+  ~PresentationConnectionStateChangeInfo() = default;
+
+  PresentationConnectionState state;
+
+  // |close_reason| and |messsage| are only used for state change to CLOSED.
+  PresentationConnectionCloseReason close_reason;
+  std::string message;
+};
+
+using PresentationConnectionStateChangedCallback =
+    base::Callback<void(const PresentationConnectionStateChangeInfo&)>;
+
 // An interface implemented by embedders to handle presentation API calls
 // forwarded from PresentationServiceImpl.
 class CONTENT_EXPORT PresentationServiceDelegate {