[Blink, RemotePlayback] watchAvailability() implementation.

third_party/WebKit/Source/modules/remoteplayback/RemotePlayback.idl

Index: third_party/WebKit/Source/modules/remoteplayback/RemotePlayback.idl
diff --git a/third_party/WebKit/Source/modules/remoteplayback/RemotePlayback.idl b/third_party/WebKit/Source/modules/remoteplayback/RemotePlayback.idl
index 65539fb13a522a1ee11aa1f87cc6501555212e09..64f90cad0083023fa37e113c10c184f219817bd4 100644
--- a/third_party/WebKit/Source/modules/remoteplayback/RemotePlayback.idl
+++ b/third_party/WebKit/Source/modules/remoteplayback/RemotePlayback.idl
@@ -9,6 +9,8 @@ enum RemotePlaybackState {
     "disconnected"
 };
 
+callback RemotePlaybackAvailabilityCallback = void(boolean available);
+
 [
     ActiveScriptWrappable,
     DependentLifetime,
@@ -19,6 +21,7 @@ enum RemotePlaybackState {
     attribute EventHandler onconnect;
     attribute EventHandler ondisconnect;
 
-    [CallWith=ScriptState] Promise<RemotePlaybackAvailability> getAvailability();
+    [CallWith=ScriptState, Custom=CallEpilogue] Promise<long> watchAvailability(RemotePlaybackAvailabilityCallback callback);
+    [CallWith=ScriptState, Custom=CallPrologue] Promise<void> cancelWatchAvailability(optional long id);

[haraken, 2016/10/15 01:52:45]

Where is the custom bindings written?

[whywhat, 2016/10/16 03:41:40]

Nowhere yet as I'm not even sure how to write it. See my earlier reply to
bashi@'s suggestion.

[bashi, 2016/10/17 00:11:05]

You will need to add a new file under Source/bindings/modules/v8/custom. The new
file will be called V8RemotePlaybackCustom.cpp and it would have:
- void V8RemotePlayback::watchAvailabilityMethodEpilogueCustom(const
v8::FunctionCallbackInfo<v8::Value>&, RemotePlayback*)
- void V8RemotePlayback::cancelAvailabilityMethodPrologueCustom(const
v8::FunctionCallbackInfo<v8::Value>&, RemotePlayback*)

     [CallWith=ScriptState] Promise<void> prompt();
 };