[DevTools] Remove HelpScreen, turn SettingsScreen into dialog and web component.

third_party/WebKit/Source/devtools/front_end/ui/UIUtils.js

Index: third_party/WebKit/Source/devtools/front_end/ui/UIUtils.js
diff --git a/third_party/WebKit/Source/devtools/front_end/ui/UIUtils.js b/third_party/WebKit/Source/devtools/front_end/ui/UIUtils.js
index ee9cc15b912ed0aa0c95aab3de7d38c16412c7ae..5662a50e6e530103249252898d7a542848134030 100644
--- a/third_party/WebKit/Source/devtools/front_end/ui/UIUtils.js
+++ b/third_party/WebKit/Source/devtools/front_end/ui/UIUtils.js
@@ -204,7 +204,8 @@ WebInspector.GlassPane = function(document, dimmed)
 {
     this.element = createElement("div");
     var background = dimmed ? "rgba(255, 255, 255, 0.5)" : "transparent";
-    this.element.style.cssText = "position:absolute;top:0;bottom:0;left:0;right:0;background-color:" + background + ";z-index:3000;overflow:hidden;";
+    this._zIndex = WebInspector._glassPane ? WebInspector._glassPane._zIndex + 1000 : 3000; // Deliberately starts with 3000 to hide other z-indexed elements below.
+    this.element.style.cssText = "position:absolute;top:0;bottom:0;left:0;right:0;background-color:" + background + ";z-index:" + this._zIndex + ";overflow:hidden;";
     document.body.appendChild(this.element);
     WebInspector._glassPane = this;
 }
@@ -219,6 +220,9 @@ WebInspector.GlassPane.prototype = {
     }
 }
 
+/** @type {!WebInspector.GlassPane|undefined} */
+WebInspector._glassPane;
+
 /**
  * @type {!Array.<!WebInspector.Widget|!WebInspector.Dialog>}
  */
@@ -771,17 +775,17 @@ WebInspector.setCurrentFocusElement = function(x)
         WebInspector._previousFocusElement = WebInspector._currentFocusElement;
     WebInspector._currentFocusElement = x;
 
-    if (WebInspector._currentFocusElement) {
-        WebInspector._currentFocusElement.focus();
+    if (x) {
+        x.focus();
 
         // Make a caret selection inside the new element if there isn't a range selection and there isn't already a caret selection inside.
         // This is needed (at least) to remove caret from console when focus is moved to some element in the panel.
         // The code below should not be applied to text fields and text areas, hence _isTextEditingElement check.
         var selection = x.getComponentSelection();
-        if (!WebInspector._isTextEditingElement(WebInspector._currentFocusElement) && selection.isCollapsed && !WebInspector._currentFocusElement.isInsertionCaretInside()) {
-            var selectionRange = WebInspector._currentFocusElement.ownerDocument.createRange();
-            selectionRange.setStart(WebInspector._currentFocusElement, 0);
-            selectionRange.setEnd(WebInspector._currentFocusElement, 0);
+        if (!WebInspector._isTextEditingElement(x) && selection.isCollapsed && !x.isInsertionCaretInside()) {
+            var selectionRange = x.ownerDocument.createRange();
+            selectionRange.setStart(x, 0);
+            selectionRange.setEnd(x, 0);
 
             selection.removeAllRanges();
             selection.addRange(selectionRange);