mac: Add support for asynchronous dictionary lookup

content/renderer/text_input_client_observer.cc

Index: content/renderer/text_input_client_observer.cc
diff --git a/content/renderer/text_input_client_observer.cc b/content/renderer/text_input_client_observer.cc
index 5ce95ff6093742ac828679019e22a9cbee097912..0211454c96ab62375d370672eccb16224c51b2fa 100644
--- a/content/renderer/text_input_client_observer.cc
+++ b/content/renderer/text_input_client_observer.cc
@@ -29,6 +29,8 @@ TextInputClientObserver::~TextInputClientObserver() {
 bool TextInputClientObserver::OnMessageReceived(const IPC::Message& message) {
   bool handled = true;
   IPC_BEGIN_MESSAGE_MAP(TextInputClientObserver, message)
+    IPC_MESSAGE_HANDLER(TextInputClientMsg_StringAtPoint,
+                        OnStringAtPoint)
     IPC_MESSAGE_HANDLER(TextInputClientMsg_CharacterIndexForPoint,
                         OnCharacterIndexForPoint)
     IPC_MESSAGE_HANDLER(TextInputClientMsg_FirstRectForCharacterRange,
@@ -43,6 +45,21 @@ blink::WebView* TextInputClientObserver::webview() {
   return render_view()->GetWebView();
 }
 
+void TextInputClientObserver::OnStringAtPoint(gfx::Point point) {
+#if defined(OS_MACOSX)
+  blink::WebPoint baselinePoint;
+  NSAttributedString* string = blink::WebSubstringUtil::attributedWordAtPoint(
+      webview(), point, baselinePoint);
+
+  scoped_ptr<const mac::AttributedStringCoder::EncodedString> encoded(
+      mac::AttributedStringCoder::Encode(string));
+  Send(new TextInputClientReplyMsg_GotStringAtPoint(
+      routing_id(), *encoded.get(), baselinePoint));
+#else
+  NOTIMPLEMENTED();
+#endif
+}
+
 void TextInputClientObserver::OnCharacterIndexForPoint(gfx::Point point) {
   blink::WebPoint web_point(point);
   size_t index = webview()->focusedFrame()->characterIndexForPoint(web_point);