Move stringify, form, navigation and scroll methods out of core.js.

ios/web/web_state/js/resources/scroll_workaround.js

+// Copyright 2017 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.
+
+/**
+ * @fileoverview APIs used for the scroll workaround. See crbug.com/554257.
+ */
+
+goog.provide('__crWeb.scrollWorkaround');
+
+/** Beginning of anonymous object */
+(function() {
+
+  /** @private */
+  var webViewScrollViewIsDragging_ = false;
+
+  /**
+   * Tracks whether user is in the middle of scrolling/dragging. If user is
+   * scrolling, ignore window.scrollTo() until user stops scrolling.
+   */
+  __gCrWeb['setWebViewScrollViewIsDragging'] = function(state) {
+    webViewScrollViewIsDragging_ = state;
+  };
+
+  /** @private */
+  var originalWindowScrollTo_ = window.scrollTo;
+
+  /**
+   * Wraps the original window.scrollTo() to suppress it as long as
+   * webViewScrollViewIsDragging is true.
+   */
+  window.scrollTo = function(x, y) {
+    if (webViewScrollViewIsDragging_)
+      return;
+    originalWindowScrollTo_(x, y);
+  };
+
+}())  // End of anonymouse object