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

Source/core/css/CSSGrammar.y.in

 /*
  *  Copyright (C) 2002-2003 Lars Knoll (knoll@kde.org)
  *  Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013 Apple Inc. All rights reserved.
  *  Copyright (C) 2006 Alexey Proskuryakov (ap@nypop.com)
  *  Copyright (C) 2008 Eric Seidel <eric@webkit.org>
  *  Copyright (C) 2012 Intel Corporation. All rights reserved.
  *
  *  This library is free software; you can redistribute it and/or
  *  modify it under the terms of the GNU Lesser General Public
  *  License as published by the Free Software Foundation; either
@@ skipping 214 matching lines @@
 %type <rule> rule
 %type <rule> valid_rule
 %type <ruleList> block_rule_body
 %type <ruleList> block_rule_list 
 %type <ruleList> region_block_rule_body
 %type <ruleList> region_block_rule_list
 %type <rule> block_rule
 %type <rule> block_valid_rule
 %type <rule> region
 %type <rule> supports
-#if ENABLE_CSS_DEVICE_ADAPTATION
 %type <rule> viewport
-#endif
 %type <rule> filter
 
 %type <string> maybe_ns_prefix
 
 %type <string> namespace_selector
 
 %type <string> string_or_uri
 %type <string> ident_or_string
 %type <string> medium
 %type <marginBox> margin_sym
@@ skipping 185 matching lines @@
     ruleset
   | media
   | page
   | font_face
   | keyframes
   | namespace
   | import
   | region
   | supports
   | host
-#if ENABLE_CSS_DEVICE_ADAPTATION
   | viewport
-#endif
   | filter
   ;
 
 rule:
     valid_rule {
         parser->m_hadSyntacticallyValidCSSRule = true;
     }
   | invalid_rule
   ;
 
@@ skipping 29 matching lines @@
   }
   ;
 
 block_valid_rule:
     ruleset
   | page
   | font_face
   | media
   | keyframes
   | supports
-#if ENABLE_CSS_DEVICE_ADAPTATION
   | viewport
-#endif
   | filter
   ;
 
 block_rule:
     block_valid_rule
   | invalid_rule
   | namespace
   | import
   | region
   ;
@@ skipping 503 matching lines @@
     before_host_rule HOST_SYM at_rule_header_end_maybe_space
     '{' at_rule_body_start maybe_space block_rule_body closing_brace {
         $$ = parser->createHostRule($7);
     }
     | before_host_rule HOST_SYM at_rule_recovery {
         $$ = 0;
         parser->endRuleBody(true);
     }
     ;
 
-#if ENABLE_CSS_DEVICE_ADAPTATION
 before_viewport_rule:
     /* empty */ {
         parser->markViewportRuleBodyStart();
         parser->startRuleHeader(CSSRuleSourceData::VIEWPORT_RULE);
     }
     ;
 
 viewport:
     before_viewport_rule WEBKIT_VIEWPORT_RULE_SYM at_rule_header_end_maybe_space
     '{' at_rule_body_start maybe_space_before_declaration declaration_list closing_brace {
         $$ = parser->createViewportRule();
         parser->markViewportRuleBodyEnd();
     }
     | before_viewport_rule WEBKIT_VIEWPORT_RULE_SYM at_rule_recovery {
         $$ = 0;
         parser->endRuleBody(true);
         parser->markViewportRuleBodyEnd();
     }
 ;
-#endif
 
 region_selector:
     selector_list {
         if ($1) {
             parser->setReusableRegionSelectorVector($1);
             $$ = parser->reusableRegionSelectorVector();
         }
         else
             $$ = 0;
     }
@@ skipping 934 matching lines @@
 
 rule_error_recovery:
     /* empty */
   | rule_error_recovery error
   | rule_error_recovery invalid_square_brackets_block
   | rule_error_recovery invalid_parentheses_block
     ;
 
 %%