Implement setSinkId() for media elements without src.

third_party/WebKit/Source/modules/audio_output_devices/HTMLMediaElementAudioOutputDevice.cpp

Index: third_party/WebKit/Source/modules/audio_output_devices/HTMLMediaElementAudioOutputDevice.cpp
diff --git a/third_party/WebKit/Source/modules/audio_output_devices/HTMLMediaElementAudioOutputDevice.cpp b/third_party/WebKit/Source/modules/audio_output_devices/HTMLMediaElementAudioOutputDevice.cpp
index 930dc3c40b88e366c893b33e4f2691cb812f706b..758d458090bf92187056eb9a75f466797f824ea0 100644
--- a/third_party/WebKit/Source/modules/audio_output_devices/HTMLMediaElementAudioOutputDevice.cpp
+++ b/third_party/WebKit/Source/modules/audio_output_devices/HTMLMediaElementAudioOutputDevice.cpp
@@ -8,6 +8,7 @@
 #include "bindings/core/v8/ScriptPromiseResolver.h"
 #include "bindings/core/v8/ScriptState.h"
 #include "core/dom/ExecutionContext.h"
+#include "modules/audio_output_devices/AudioOutputDeviceClient.h"
 #include "modules/audio_output_devices/SetSinkIdCallbacks.h"
 #include "public/platform/WebSecurityOrigin.h"
 
@@ -34,14 +35,23 @@ ScriptPromise HTMLMediaElementAudioOutputDevice::setSinkId(ScriptState* scriptSt
     ASSERT(scriptState);
 
     WebMediaPlayer* webMediaPlayer = element.webMediaPlayer();
-    if (!webMediaPlayer)
-        return ScriptPromise::rejectWithDOMException(scriptState, DOMException::create(AbortError, "No media player available"));
-
+    ScriptPromiseResolver* resolver = ScriptPromiseResolver::create(scriptState);
+    OwnPtr<SetSinkIdCallbacks> callbacks = adoptPtr(new SetSinkIdCallbacks(resolver, element, sinkId));
+    ScriptPromise promise = resolver->promise();
     ExecutionContext* context = scriptState->executionContext();
     ASSERT(context && context->isDocument());
 
-    ScriptPromiseResolver* resolver = ScriptPromiseResolver::create(scriptState);
-    webMediaPlayer->setSinkId(sinkId, WebSecurityOrigin(context->securityOrigin()), new SetSinkIdCallbacks(resolver, element, sinkId));
+    if (webMediaPlayer) {
+        webMediaPlayer->setSinkId(sinkId, WebSecurityOrigin(context->securityOrigin()), callbacks.leakPtr());

[philipj_slow, 2015/11/02 13:04:07]

Is it correct that it's callbacks.leakPtr() in one branch but
callbacks.release() in the other? Without a comment, it looks like a mistake.

[Guido Urdaneta, 2015/11/02 16:30:04]

Added comment explaining why leakPtr(). I can add another one explaining
release() if you consider it helps clarify intent further.

+    } else {
+        if (AudioOutputDeviceClient* client = AudioOutputDeviceClient::from(context)) {
+            client->checkIfAudioSinkExistsAndIsAuthorized(context, sinkId, callbacks.release());
+        } else {
+            // The context has been detached. The promise will never settle.

[philipj_slow, 2015/11/02 13:04:07]

When will this happen? I assume that the spec doesn't allow the promise to
remain unsettled in any situation, so if this is the only sensible behavior to
implement then the spec should change to somehow allow this.

[Guido Urdaneta, 2015/11/02 16:30:04]

I changed it to return a SecurityError, which seems appropriate given that the
problem in this case is that there is no way to check permissions.
Hitting this case should be very rare.

+            ASSERT(context->activeDOMObjectsAreStopped());
+        }
+    }
+
     return resolver->promise();
 }