Add compile flag for enabling the compostior

sky/engine/web/WebSettingsImpl.cpp

 /*
  * Copyright (C) 2009 Google 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:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 34 matching lines @@
     , m_showPaintRects(false)
     , m_renderVSyncNotificationEnabled(false)
     , m_deferredImageDecodingEnabled(false)
     , m_supportDeprecatedTargetDensityDPI(false)
     , m_shrinksViewportContentToFit(false)
     , m_mainFrameResizesAreOrientationChanges(false)
 {
     ASSERT(settings);
 }
 
+bool WebSettingsImpl::compositorIsEnabled() const
+{
+#if ENABLE(COMPOSITOR)
+    return true;
+#else
+    return false;
+#endif
+}
+
 void WebSettingsImpl::setStandardFontFamily(const WebString& font, UScriptCode script)
 {
     if (m_settings->genericFontFamilySettings().updateStandard(font, script))
         m_settings->notifyGenericFontFamilyChange();
 }
 
 void WebSettingsImpl::setFixedFontFamily(const WebString& font, UScriptCode script)
 {
     if (m_settings->genericFontFamilySettings().updateFixed(font, script))
         m_settings->notifyGenericFontFamilyChange();
@@ skipping 322 matching lines @@
 {
     m_mainFrameResizesAreOrientationChanges = enabled;
 }
 
 void WebSettingsImpl::setV8CacheOptions(V8CacheOptions options)
 {
     m_settings->setV8CacheOptions(static_cast<blink::V8CacheOptions>(options));
 }
 
 } // namespace blink