Implement a part of ProcessingInstruction by using PrivateScript

Source/core/dom/ProcessingInstruction.js

Index: Source/core/dom/ProcessingInstruction.js
diff --git a/Source/core/dom/ProcessingInstruction.js b/Source/core/dom/ProcessingInstruction.js
new file mode 100644
index 0000000000000000000000000000000000000000..d5a03acc839c4bff738031710e04bd1dde3a81a3
--- /dev/null
+++ b/Source/core/dom/ProcessingInstruction.js
@@ -0,0 +1,69 @@
+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+"use strict";
+
+installClass("ProcessingInstruction", function(global, ProcessingInstructionPrototype) {
+
+    ProcessingInstructionPrototype.registerSheet = function(parsing) {
+        if (!global.document.xslStyleSheetInitialized_) {
+            global.document.parsing = parsing;
+            global.document.xslStyleSheetLoaded = [];
+            global.document.xslStyleSheet = [];
+            global.document.xslStyleSheetInitialized_ = true;
+
+            global.document.addEventListener('DOMContentLoaded', function() {
+                global.document.parsing = false;
+                var found = false;
+                for (var index = 0; index < global.document.xslStyleSheetLoaded.length; index++) {
+                    if (global.document.xslStyleSheetLoaded[index] == global.document.xslStyleSheet[0]) {
+                        found = true;
+                        break;
+                    }
+                }
+                if (!found)
+                    return;
+                if (global.document.transformSourceDocument)
+                    return;
+                global.document.applyXSLTransform(global.document.xslStyleSheet[0]);
+            }, false);
+        }
+
+        if (global.document.xslStyleSheet.length == 0) {
+            global.document.xslStyleSheet.push(this);
+            return;
+        }
+
+        for (var index = 0; index < global.document.xslStyleSheet.length; index++) {
+            var position = global.document.xslStyleSheet[index].compareDocumentPosition(this);
+            if (position & Node.DOCUMENT_POSITION_PRECEDING) {
+                global.document.xslStyleSheet.splice(index, 0, this);
+                return;
+            }
+        }
+    }
+
+    ProcessingInstructionPrototype.unregisterSheet = function() {
+        for (var index = 0; index < global.document.xslStyleSheet.length; index++) {
+            if (global.document.xslStyleSheet[index] == this) {
+                global.document.xslStyleSheet.splice(index, 1);
+                break;
+            }
+        }
+        for (var index = 0; index < global.document.xslStyleSheetLoaded.length; index++) {
+            if (!global.document.xslStyleSheetLoaded[index] == this) {
+                global.document.xslStyleSheetLoaded.splice(index, 1);
+                break;
+            }
+        }
+    }
+
+    ProcessingInstructionPrototype.sheetLoadedCallback = function() {
+        global.document.xslStyleSheetLoaded.push(this);
+        if (global.document.xslStyleSheet[0] != this || global.document.parsing || global.document.transformSourceDocument)
+            return;
+        global.document.applyXSLTransform(global.document.xslStyleSheet[0]);
+    }
+});
+