Warn developers about deprecated features only once per page-load.

Source/core/page/Page.h

 /*
  * Copyright (C) 2006, 2007, 2008, 2009, 2010, 2013 Apple Inc. All rights reserved.
  * Copyright (C) 2008 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Library General Public License for more details.
  *
  * You should have received a copy of the GNU Library General Public License
  * along with this library; see the file COPYING.LIB.  If not, write to
  * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  * Boston, MA 02110-1301, USA.
  */
 
 #ifndef Page_h
 #define Page_h
 
-#include "UseCounter.h"
+#include "DeprecationAgent.h"
 #include "FindOptions.h"
 #include "FrameLoaderTypes.h"
 #include "LayoutMilestones.h"
 #include "LayoutRect.h"
 #include "PageVisibilityState.h"
 #include "Pagination.h"
 #include "PlatformScreen.h"
 #include "Region.h"
 #include "Supplementable.h"
+#include "UseCounter.h"
 #include "ViewportArguments.h"
 #include <wtf/Forward.h>
 #include <wtf/HashMap.h>
 #include <wtf/HashSet.h>
 #include <wtf/Noncopyable.h>
 #include <wtf/text/WTFString.h>
 
 #if OS(SOLARIS)
 #include <sys/time.h> // For time_t structure.
 #endif
 
 namespace WebCore {
 
 class AlternativeTextClient;
 class BackForwardController;
 class BackForwardList;
 class Chrome;
 class ChromeClient;
 class ClientRectList;
 class ContextMenuClient;
 class ContextMenuController;
 class Document;
+class DeprecationAgent;
 class DragCaretController;
 class DragClient;
 class DragController;
 class EditorClient;
 class FocusController;
 class Frame;
 class FrameSelection;
 class HaltablePlugin;
 class HistoryItem;
 class InspectorClient;
@@ skipping 116 matching lines @@
 
     String mainThreadScrollingReasonsAsText();
     PassRefPtr<ClientRectList> nonFastScrollableRects(const Frame*);
 
     Settings* settings() const { return m_settings.get(); }
     ProgressTracker* progress() const { return m_progress.get(); }
     BackForwardController* backForward() const { return m_backForwardController.get(); }
 
     UseCounter* useCounter() { return &m_UseCounter; }
 
+    DeprecationAgent* deprecationAgent() { return &m_deprecationAgent; }
+
     enum ViewMode {
         ViewModeInvalid,
         ViewModeWindowed,
         ViewModeFloating,
         ViewModeFullscreen,
         ViewModeMaximized,
         ViewModeMinimized
     };
     static ViewMode stringToViewMode(const String&);
 
@@ skipping 165 matching lines @@
     mutable RefPtr<PluginData> m_pluginData;
 
     RefPtr<RenderTheme> m_theme;
 
     EditorClient* m_editorClient;
     PlugInClient* m_plugInClient;
     ValidationMessageClient* m_validationMessageClient;
 
     UseCounter m_UseCounter;
 
+    DeprecationAgent m_deprecationAgent;
+
     int m_subframeCount;
     String m_groupName;
     bool m_openedByDOM;
 
     bool m_tabKeyCyclesThroughElements;
     bool m_defersLoading;
     unsigned m_defersLoadingCallCount;
 
     bool m_inLowQualityInterpolationMode;
     bool m_cookieEnabled;
@@ skipping 55 matching lines @@
 inline PageGroup& Page::group()
 {
     if (!m_group)
         initGroup();
     return *m_group;
 }
 
 } // namespace WebCore
     
 #endif // Page_h