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

Source/bindings/v8/custom/V8CSSRuleCustom.cpp

Index: Source/bindings/v8/custom/V8CSSRuleCustom.cpp
diff --git a/Source/bindings/v8/custom/V8CSSRuleCustom.cpp b/Source/bindings/v8/custom/V8CSSRuleCustom.cpp
index e8e505f1d152a16d2f0ea87a0287538b13e27a01..143cd8c00152ee737e1862b6969e3b687fd43d8d 100644
--- a/Source/bindings/v8/custom/V8CSSRuleCustom.cpp
+++ b/Source/bindings/v8/custom/V8CSSRuleCustom.cpp
@@ -43,10 +43,7 @@
 #include "V8CSSRegionRule.h"
 #include "V8CSSStyleRule.h"
 #include "V8CSSSupportsRule.h"
-
-#if ENABLE(CSS_DEVICE_ADAPTATION)
 #include "V8CSSViewportRule.h"
-#endif
 
 namespace WebCore {
 
@@ -77,10 +74,8 @@ v8::Handle<v8::Object> wrap(CSSRule* impl, v8::Handle<v8::Object> creationContex
         return wrap(static_cast<CSSKeyframesRule*>(impl), creationContext, isolate);
     case CSSRule::SUPPORTS_RULE:
         return wrap(static_cast<CSSSupportsRule*>(impl), creationContext, isolate);
-#if ENABLE(CSS_DEVICE_ADAPTATION)
     case CSSRule::WEBKIT_VIEWPORT_RULE:
-        return wrap(static_cast<WebKitCSSViewportRule*>(impl), creationContext, isolate);
-#endif
+        return wrap(static_cast<CSSViewportRule*>(impl), creationContext, isolate);
     case CSSRule::WEBKIT_REGION_RULE:
         return wrap(static_cast<CSSRegionRule*>(impl), creationContext, isolate);
     case CSSRule::HOST_RULE: