remove unused cachedBitmap from ImageBufferSurface

Source/platform/graphics/RecordingImageBufferSurface.cpp

 // Copyright 2014 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 "config.h"
 
 #include "platform/graphics/RecordingImageBufferSurface.h"
 
 #include "platform/graphics/ExpensiveCanvasHeuristicParameters.h"
 #include "platform/graphics/GraphicsContext.h"
@@ skipping 248 matching lines @@
     return ImageBufferSurface::layer();
 }
 
 bool RecordingImageBufferSurface::isAccelerated() const
 {
     if (m_fallbackSurface)
         return m_fallbackSurface->isAccelerated();
     return ImageBufferSurface::isAccelerated();
 }
 
-bool RecordingImageBufferSurface::cachedBitmapEnabled() const
-{
-    if (m_fallbackSurface)
-        return m_fallbackSurface->cachedBitmapEnabled();
-    return ImageBufferSurface::cachedBitmapEnabled();
-}
-
-const SkBitmap& RecordingImageBufferSurface::cachedBitmap() const
-{
-    if (m_fallbackSurface)
-        return m_fallbackSurface->cachedBitmap();
-    return ImageBufferSurface::cachedBitmap();
-}
-
-void RecordingImageBufferSurface::invalidateCachedBitmap()
-{
-    if (m_fallbackSurface)
-        m_fallbackSurface->invalidateCachedBitmap();
-    else
-        ImageBufferSurface::invalidateCachedBitmap();
-}
-
-void RecordingImageBufferSurface::updateCachedBitmapIfNeeded()
-{
-    if (m_fallbackSurface)
-        m_fallbackSurface->updateCachedBitmapIfNeeded();
-    else
-        ImageBufferSurface::updateCachedBitmapIfNeeded();
-}
-
 void RecordingImageBufferSurface::setIsHidden(bool hidden)
 {
     if (m_fallbackSurface)
         m_fallbackSurface->setIsHidden(hidden);
     else
         ImageBufferSurface::setIsHidden(hidden);
 }
 
 } // namespace blink