Add compile flag for enabling the compostior

sky/engine/core/rendering/compositing/RenderLayerCompositor.cpp

 /*
  * Copyright (C) 2009, 2010 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 97 matching lines @@
     if (rootShouldAlwaysComposite()) {
         // FIXME: Is this needed? It was added in https://bugs.webkit.org/show_bug.cgi?id=26651.
         // No tests fail if it's deleted.
         setNeedsCompositingUpdate(CompositingUpdateRebuildTree);
         setCompositingModeEnabled(true);
     }
 }
 
 bool RenderLayerCompositor::rootShouldAlwaysComposite() const
 {
-    // FIXME(sky): Remove
+#if ENABLE(COMPOSITOR)
     return true;
+#else
+    return false;
+#endif
 }
 
 void RenderLayerCompositor::updateAcceleratedCompositingSettings()
 {
     m_compositingReasonFinder.updateTriggers();
     m_rootShouldAlwaysCompositeDirty = true;
 }
 
+bool RenderLayerCompositor::hasAcceleratedCompositing() const
+{
+#if ENABLE(COMPOSITOR)
+    return true;
+#else
+    return false;
+#endif
+}
+
 bool RenderLayerCompositor::layerSquashingEnabled() const
 {
     if (!RuntimeEnabledFeatures::layerSquashingEnabled())
         return false;
     return true;
 }
 
 bool RenderLayerCompositor::preferCompositingToLCDTextEnabled() const
 {
     return m_compositingReasonFinder.hasOverflowScrollTrigger();
@@ skipping 65 matching lines @@
     CompositingInputsUpdater::assertNeedsCompositingInputsUpdateBitsCleared(rootRenderLayer());
 #endif
 }
 
 void RenderLayerCompositor::updateIfNeeded()
 {
     CompositingUpdateType updateType = m_pendingUpdateType;
     m_pendingUpdateType = CompositingUpdateNone;
 
     if (!hasAcceleratedCompositing()) {
+#if ENABLE(COMPOSITOR)
         updateWithoutAcceleratedCompositing(updateType);
+#endif
         return;
     }
 
     if (updateType == CompositingUpdateNone)
         return;
 
     RenderLayer* updateRoot = rootRenderLayer();
 
     Vector<RenderLayer*> layersNeedingPaintInvalidation;
 
@@ skipping 535 matching lines @@
     } else if (graphicsLayer == m_scrollLayer.get()) {
         name = "LocalFrame Scrolling Layer";
     } else {
         ASSERT_NOT_REACHED();
     }
 
     return name;
 }
 
 } // namespace blink