A quick fix for Issue 18708....

webkit/api/src/gtk/WebInputEventFactory.cpp

 /*
  * Copyright (C) 2006-2009 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 190 matching lines @@
 
     // The key code tells us which physical key was pressed (for example, the
     // A key went down or up).  It does not determine whether A should be lower
     // or upper case.  This is what text does, which should be the keyval.
     result.windowsKeyCode = gdkEventToWindowsKeyCode(event);
     result.nativeKeyCode = event->hardware_keycode;
 
     switch (event->keyval) {
     // We need to treat the enter key as a key press of character \r.  This
     // is apparently just how webkit handles it and what it expects.
+    // On the other hand, IE and Firefox treat the control+enter keys as a key
+    // press of character '\n'. We also emulate this behavior since Google
+    // Docs and Spreadsheets depend on it.
     case GDK_ISO_Enter:
     case GDK_KP_Enter:
     case GDK_Return:
-        result.unmodifiedText[0] = result.text[0] = static_cast<WebUChar>('\r');
+        result.unmodifiedText[0] = result.text[0] =
+            static_cast<WebUChar>((event->state & GDK_CONTROL_MASK) ? '\n' : '\r');
         break;
     default:
         // This should set text to 0 when it's not a real character.
         // FIXME: fix for non BMP chars
         // TODO(james.su@gmail.com):
         // Support control characters input like Windows.
         // See: http://en.wikipedia.org/wiki/Control_characters
         result.unmodifiedText[0] = result.text[0] =
             static_cast<WebUChar>(gdk_keyval_to_unicode(event->keyval));
     }
@@ skipping 158 matching lines @@
     case GDK_SCROLL_RIGHT:
         result.deltaX = -scrollbarPixelsPerTick;
         result.wheelTicksX = 1;
         break;
     }
 
     return result;
 }
 
 } // namespace WebKit