DevTools: allow reattaching main target live.

chrome/browser/devtools/devtools_embedder_message_dispatcher.h

Index: chrome/browser/devtools/devtools_embedder_message_dispatcher.h
diff --git a/chrome/browser/devtools/devtools_embedder_message_dispatcher.h b/chrome/browser/devtools/devtools_embedder_message_dispatcher.h
index 141392fae8f02ffaddbcb18736eea682d3765453..fd8665bfa74c17d6c79f32d201c59397d0534188 100644
--- a/chrome/browser/devtools/devtools_embedder_message_dispatcher.h
+++ b/chrome/browser/devtools/devtools_embedder_message_dispatcher.h
@@ -88,6 +88,7 @@ class DevToolsEmbedderMessageDispatcher {
     virtual void SendJsonRequest(const DispatchCallback& callback,
                                  const std::string& browser_id,
                                  const std::string& url) = 0;
+    virtual void Reattach(const DispatchCallback& callback) = 0;
     virtual void ReadyForTest() = 0;
   };