Remove CSS regions support, keeping a bare minimum to support "region-based" multicol.

Source/core/css/WebKitCSSRegionRule.idl

Index: Source/core/css/WebKitCSSRegionRule.idl
diff --git a/Source/core/css/WebKitCSSRegionRule.idl b/Source/core/css/WebKitCSSRegionRule.idl
deleted file mode 100644
index 681134480485aafeb9f9e140d4840f0be5777aaa..0000000000000000000000000000000000000000
--- a/Source/core/css/WebKitCSSRegionRule.idl
+++ /dev/null
@@ -1,36 +0,0 @@
-/*
- * Copyright (C) 2011 Adobe Systems Incorporated. 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
- *    disclaimer.
- * 2. Redistributions in binary form must reproduce the above
- *    copyright notice, this list of conditions and the following
- *    disclaimer in the documentation and/or other materials
- *    provided with the distribution.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER "AS IS" AND ANY
- * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
- * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
- * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER BE
- * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
- * OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
- * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
- * 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.
- */
-
-[
-    RuntimeEnabled=CSSRegions,
-    ImplementedAs=CSSRegionRule
-] interface WebKitCSSRegionRule : CSSRule {
-    readonly attribute CSSRuleList cssRules;
-};
-