[Mac] Cmd-Return in the omnibox should revert the omnibox text back to its or...

chrome/browser/autocomplete/autocomplete_edit_view_mac.mm

 // Copyright (c) 2009 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/autocomplete/autocomplete_edit_view_mac.h"
 
 #include <Carbon/Carbon.h>  // kVK_Return
 
 #include "app/clipboard/clipboard.h"
 #include "app/gfx/font.h"
@@ skipping 807 matching lines @@
   }
 
   // |-noop:| is sent when the user presses Cmd+Return. Override the no-op
   // behavior with the proper WindowOpenDisposition.
   NSEvent* event = [NSApp currentEvent];
   if (cmd == @selector(insertNewline:) ||
      (cmd == @selector(noop:) && [event keyCode] == kVK_Return)) {
     WindowOpenDisposition disposition =
         event_utils::WindowOpenDispositionFromNSEvent(event);
     edit_view_->AcceptInput(disposition, false);
+    // Opening a URL in a background tab should also revert the omnibox contents
+    // to their original state.  We cannot do a blanket revert in OpenURL()
+    // because middle-clicks also open in a new background tab, but those should
+    // not revert the omnibox text.
+    edit_view_->RevertAll();
     return YES;
   }
 
   // Option-Return
   if (cmd == @selector(insertNewlineIgnoringFieldEditor:)) {
     edit_view_->AcceptInput(NEW_FOREGROUND_TAB, false);
     return YES;
   }
 
   // When the user does Control-Enter, the existing content has "www."
@@ skipping 51 matching lines @@
   // TODO(shess): Figure out where the selection belongs.  On GTK,
   // it's set to the start of the text.
 }
 
 // Signal that we've lost focus when the window resigns key.
 - (void)windowDidResignKey:(NSNotification*)notification {
   edit_view_->OnDidResignKey();
 }
 
 @end