For non-editable content, selection editor commands are disabled

Source/core/page/EventHandler.cpp

 /*
  * Copyright (C) 2006, 2007, 2008, 2009, 2010, 2011 Apple Inc. All rights reserved.
  * Copyright (C) 2006 Alexey Proskuryakov (ap@webkit.org)
  * Copyright (C) 2012 Digia Plc. and/or its subsidiary(-ies)
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
@@ skipping 744 matching lines @@
     m_capturesDragging = false;
     m_mouseDownMayStartDrag = false;
     m_mouseDownMayStartSelect = false;
     m_mouseDownMayStartAutoscroll = false;
     m_mouseDownWasInSubframe = false;
 
     bool handled = false;
 
     // Clear the selection if the mouse didn't move after the last mouse
     // press and it's not a context menu click.  We do this so when clicking
-    // on the selection, the selection goes away.  However, if we are
-    // editing, place the caret.
+    // on the selection, the selection goes away. For readonly texts
+    // we do need to know the position of the caret for any selection
+    // using keyboard shortcuts as its currently working in non-webkit
+    // based browsers for ex: firefox. Therefore, place the caret even
+    // for non-editable texts.
     if (m_mouseDownWasSingleClickInSelection && m_selectionInitiationState != ExtendedSelection
             && m_dragStartPos == event.event().position()
             && m_frame->selection().isRange()
             && event.event().button() != RightButton) {
         VisibleSelection newSelection;
         Node* node = event.targetNode();
-        bool caretBrowsing = m_frame->settings() && m_frame->settings()->caretBrowsingEnabled();
-        if (node && node->renderer() && (caretBrowsing || node->rendererIsEditable())) {
+        if (node && node->renderer()) {

[Yuta Kitamura, 2014/06/04 08:19:38]

I think this change means that you will get a caret if you
click on a (non-input, non-editable) normal text, right?
If I'm not mistaken, this change may be going to confuse
people, since it changes the behavior of a click on
vast majority of areas of the screen (rendered text nodes).

[b.rout, 2014/06/04 12:53:04]

It will not show the caret, but it will set selection type to caret and 
position of the caret. Entry to the if block is only when we click 
within a selected section. For non-editable content, the selection type
was set as none since it was not allowed to set the position. And with 
selection type none we won't be able to select.

             VisiblePosition pos = VisiblePosition(node->renderer()->positionForPoint(event.localPoint()));
             newSelection = VisibleSelection(pos);
         }
 
         setSelectionIfNeeded(m_frame->selection(), newSelection);
 
         handled = true;
     }
 
     m_frame->selection().notifyRendererOfSelectionChange(UserTriggered);
@@ skipping 2948 matching lines @@
 unsigned EventHandler::accessKeyModifiers()
 {
 #if OS(MACOSX)
     return PlatformEvent::CtrlKey | PlatformEvent::AltKey;
 #else
     return PlatformEvent::AltKey;
 #endif
 }
 
 } // namespace WebCore