Adds Mojo IDL.

third_party/WebKit/Source/core/mojo/MojoHandle.idl

Index: third_party/WebKit/Source/core/mojo/MojoHandle.idl
diff --git a/third_party/WebKit/Source/core/testing/DeathAwareScriptWrappable.idl b/third_party/WebKit/Source/core/mojo/MojoHandle.idl
similarity index 77%
copy from third_party/WebKit/Source/core/testing/DeathAwareScriptWrappable.idl
copy to third_party/WebKit/Source/core/mojo/MojoHandle.idl
index fed2e45bf64b3c779ee89400e15779980fa7fb0a..aecdde02edb0a6a0c85ed42c74589d3e6fb64be2 100644
--- a/third_party/WebKit/Source/core/testing/DeathAwareScriptWrappable.idl
+++ b/third_party/WebKit/Source/core/mojo/MojoHandle.idl
@@ -2,5 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-interface DeathAwareScriptWrappable {
+[
+    NoInterfaceObject,
+] interface MojoHandle {
 };