Roll 50: Latest changes in third_party/WebKit

TBR=jacobr@google.com

Review-Url: https://codereview.chromium.org//2829163002 .
diff --git a/core/html/HTMLEmbedElement.idl b/core/html/HTMLEmbedElement.idl
index 5def601..11f7722 100644
--- a/core/html/HTMLEmbedElement.idl
+++ b/core/html/HTMLEmbedElement.idl
@@ -22,7 +22,9 @@
 
 // TODO(yukishiino): HTMLEmbedElement should not have [OverrideBuiltins].
 [
-    Custom=LegacyCallAsFunction,
+// FIXMEDART: TODO(terry): Needed to remove Custom=LegacyCallAsFunction from Embed and Object
+//                         otherwise an anonymous function is returned.
+//    Custom=LegacyCallAsFunction,
     OverrideBuiltins,
 ] interface HTMLEmbedElement : HTMLElement {
     [Reflect, URL] attribute DOMString src;
diff --git a/core/html/HTMLObjectElement.idl b/core/html/HTMLObjectElement.idl
index d0f6261..d71a2cc 100644
--- a/core/html/HTMLObjectElement.idl
+++ b/core/html/HTMLObjectElement.idl
@@ -22,7 +22,9 @@
 
 // TODO(yukishiino): HTMLObjectElement should not have [OverrideBuiltins].
 [
-    Custom=LegacyCallAsFunction,
+// FIXMEDART: TODO(terry): Needed to remove Custom=LegacyCallAsFunction from Embed and Object
+//                         otherwise an anonymous function is returned.
+//    Custom=LegacyCallAsFunction,
     OverrideBuiltins,
 ] interface HTMLObjectElement : HTMLElement {
     [Reflect, URL] attribute DOMString data;