Have HTMLMediaElement::play() return a Promise.

third_party/WebKit/Source/core/dom/DOMException.cpp

Index: third_party/WebKit/Source/core/dom/DOMException.cpp
diff --git a/third_party/WebKit/Source/core/dom/DOMException.cpp b/third_party/WebKit/Source/core/dom/DOMException.cpp
index a8b1414ebac5629ed43768d09c9953887f6c5821..144aadf29bb6214b1376f1b4c79cec2af4f07db7 100644
--- a/third_party/WebKit/Source/core/dom/DOMException.cpp
+++ b/third_party/WebKit/Source/core/dom/DOMException.cpp
@@ -81,6 +81,11 @@ static const struct CoreException {
 
     // Push API
     { "PermissionDeniedError", "User or security policy denied the request.", 0 },
+
+    { "NotAllowedError", "The request is not allowed by the user agent or the platform in the current context.", 0 },

[philipj_slow, 2016/02/02 09:56:33]

Oh, somehow I failed to notice or just forgot that
https://github.com/heycam/webidl/pull/85 was still open.

Document that this was added for HTML and Media Session, assuming you agree with
using it for activate() also?

[philipj_slow, 2016/02/04 10:54:20]

Ping.

[mlamouri (slow - plz ping), 2016/02/18 17:06:06]

Done.

+
+    // Please add new entries at the end of this list to guarantee any ordering
+    // expectations.
 };
 
 static const CoreException* getErrorEntry(ExceptionCode ec)