Move Infobars core files to the Infobars component

chrome/browser/ui/hung_plugin_tab_helper.h

Index: chrome/browser/ui/hung_plugin_tab_helper.h
diff --git a/chrome/browser/ui/hung_plugin_tab_helper.h b/chrome/browser/ui/hung_plugin_tab_helper.h
index 4457797ca8cbff5c58449115e384fbeb65a2380a..6cf1a395a86f55ca1a1b4ab39cad98ea133ceec7 100644
--- a/chrome/browser/ui/hung_plugin_tab_helper.h
+++ b/chrome/browser/ui/hung_plugin_tab_helper.h
@@ -16,12 +16,14 @@
 #include "content/public/browser/web_contents_observer.h"
 #include "content/public/browser/web_contents_user_data.h"
 
-class InfoBarDelegate;
-
 namespace base {
 class FilePath;
 }
 
+namespace infobars {
+class InfoBarDelegate;
+}
+
 // Manages per-tab state with regard to hung plugins. This only handles
 // Pepper plugins which we know are windowless. Hung NPAPI plugins (which
 // may have native windows) can not be handled with infobars and have a