Remove the ENABLE_IFRAME_SEAMLESS compile-time flag.

Source/WebCore/bindings/generic/RuntimeEnabledFeatures.h

Index: Source/WebCore/bindings/generic/RuntimeEnabledFeatures.h
diff --git a/Source/WebCore/bindings/generic/RuntimeEnabledFeatures.h b/Source/WebCore/bindings/generic/RuntimeEnabledFeatures.h
index 418880543c98bd0106eb06cae02de5d526c16931..dd240c6bfc9d30bb440cf4f0ad69f1a0f0f3e865 100644
--- a/Source/WebCore/bindings/generic/RuntimeEnabledFeatures.h
+++ b/Source/WebCore/bindings/generic/RuntimeEnabledFeatures.h
@@ -280,10 +280,8 @@ public:
     static bool experimentalContentSecurityPolicyFeaturesEnabled() { return areExperimentalContentSecurityPolicyFeaturesEnabled; }
     static void setExperimentalContentSecurityPolicyFeaturesEnabled(bool isEnabled) { areExperimentalContentSecurityPolicyFeaturesEnabled = isEnabled; }
 
-#if ENABLE(IFRAME_SEAMLESS)
     static bool seamlessIFramesEnabled() { return areSeamlessIFramesEnabled; }
     static void setSeamlessIFramesEnabled(bool isEnabled) { areSeamlessIFramesEnabled = isEnabled; }
-#endif
 
     static bool langAttributeAwareFormControlUIEnabled() { return isLangAttributeAwareFormControlUIEnabled; }
     // The lang attribute support is incomplete and should only be turned on for tests.
@@ -401,9 +399,7 @@ private:
 
     static bool areExperimentalContentSecurityPolicyFeaturesEnabled;
 
-#if ENABLE(IFRAME_SEAMLESS)
     static bool areSeamlessIFramesEnabled;
-#endif
 
 #if ENABLE(FONT_LOAD_EVENTS)
     static bool isFontLoadEventsEnabled;