Move the CSS Device Adaptation @viewport rule support behind a runtime flag

Source/core/css/CSSViewportRule.cpp

 /*
  * Copyright (C) 2012 Intel Corporation. All rights reserved.
  * Copyright (C) 2012 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
@@ skipping 13 matching lines @@
  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR
  * TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
  * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  */
 
 #include "config.h"
 #include "core/css/CSSViewportRule.h"
 
-#if ENABLE(CSS_DEVICE_ADAPTATION)
-
 #include "core/css/PropertySetCSSStyleDeclaration.h"
 #include "core/css/StylePropertySet.h"
 #include "core/css/StyleRule.h"
 #include "core/dom/WebCoreMemoryInstrumentation.h"
 #include "wtf/text/StringBuilder.h"
 
 namespace WebCore {
 
 CSSViewportRule::CSSViewportRule(StyleRuleViewport* viewportRule, CSSStyleSheet* sheet)
     : CSSRule(sheet)
@@ skipping 42 matching lines @@
 
 void CSSViewportRule::reportMemoryUsage(MemoryObjectInfo* memoryObjectInfo) const
 {
     MemoryClassInfo info(memoryObjectInfo, this, WebCoreMemoryTypes::CSS);
     CSSRule::reportMemoryUsage(memoryObjectInfo);
     info.addMember(m_viewportRule, "viewportRule");
     info.addMember(m_propertiesCSSOMWrapper, "propertiesCSSOMWrapper");
 }
 
 } // namespace WebCore
-
-#endif // ENABLE(CSS_DEVICE_ADAPTATION)