Centralize TextStream functions to remove RenderTreeAsText dependency of the filters

Source/core/platform/graphics/GraphicsLayer.cpp

 /*
  * Copyright (C) 2009 Apple 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:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 536 matching lines @@
 void GraphicsLayer::collectTrackedRepaintRects(Vector<FloatRect>& rects) const
 {
     if (!m_client->isTrackingRepaints())
         return;
 
     RepaintMap::iterator repaintIt = repaintRectMap().find(this);
     if (repaintIt != repaintRectMap().end())
         rects.append(repaintIt->value);
 }
 
-void GraphicsLayer::writeIndent(TextStream& ts, int indent)
-{
-    for (int i = 0; i != indent; ++i)
-        ts << "  ";
-}
-
 void GraphicsLayer::dumpLayer(TextStream& ts, int indent, LayerTreeFlags flags) const
 {
     writeIndent(ts, indent);
     ts << "(" << "GraphicsLayer";
 
     if (flags & LayerTreeIncludesDebugInfo) {
         ts << " " << static_cast<void*>(const_cast<GraphicsLayer*>(this));
         ts << " \"" << m_client->debugName(this) << "\"";
     }
 
@@ skipping 644 matching lines @@
 #ifndef NDEBUG
 void showGraphicsLayerTree(const WebCore::GraphicsLayer* layer)
 {
     if (!layer)
         return;
 
     String output = layer->layerTreeAsText(WebCore::LayerTreeIncludesDebugInfo);
     fprintf(stderr, "%s\n", output.utf8().data());
 }
 #endif