Implement Encoding API

Source/modules/encoding/TextEncoder.idl

Index: Source/modules/encoding/TextEncoder.idl
diff --git a/Source/core/html/ime/Composition.idl b/Source/modules/encoding/TextEncoder.idl
similarity index 82%
copy from Source/core/html/ime/Composition.idl
copy to Source/modules/encoding/TextEncoder.idl
index 494d2a06b75f42a4c55b6a01b0069e2701f412a3..ed63e2748d46c5be028e7edcbcbee6bbb3aecb75 100644
--- a/Source/core/html/ime/Composition.idl
+++ b/Source/modules/encoding/TextEncoder.idl
@@ -28,12 +28,12 @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-// http://www.w3.org/TR/ime-api/
 [
-    NoInterfaceObject
-] interface Composition {
-    readonly attribute DOMString text;
-    readonly attribute long selectionStart;
-    readonly attribute long selectionEnd;
-    sequence<unsigned long> getSegments();
+    EnabledAtRuntime=EncodingAPI,
+    GlobalContext=Window&WorkerGlobalScope,
+    Constructor([Default=NullString] optional DOMString utfLabel),
+    ConstructorRaisesException
+] interface TextEncoder {
+    readonly attribute DOMString encoding;
+    Uint8Array encode([Default=NullString] optional DOMString input, optional Dictionary options);
 };