Stop using WebCore namespace in generated code

Source/build/scripts/templates/RuntimeEnabledFeatures.cpp.tmpl

 {% from 'macros.tmpl' import license %}
 {{license()}}
 
 #include "config.h"
 #include "platform/RuntimeEnabledFeatures.h"
 
-namespace WebCore {
+namespace blink {
 
 {% for feature_set in feature_sets %}
 void RuntimeEnabledFeatures::set{{feature_set|capitalize}}FeaturesEnabled(bool enable)
 {
     {% for feature in features if feature.status == feature_set %}
     set{{feature.name}}Enabled(enable);
     {% endfor %}
 }
 
 {% endfor %}
 {% for feature in features if not feature.custom %}
 {% filter enable_conditional(feature.condition) %}
 bool RuntimeEnabledFeatures::is{{feature.name}}Enabled = {{'true' if feature.status == 'stable' else 'false'}};
 {% endfilter %}
 {% endfor %}
 
-} // namespace WebCore
+} // namespace blink