DevTools: fix DOM multiline editing, extract multiline editor API.

Source/devtools/front_end/ui/InplaceEditor.js

Index: Source/devtools/front_end/ui/InplaceEditor.js
diff --git a/Source/devtools/front_end/ui/InplaceEditor.js b/Source/devtools/front_end/ui/InplaceEditor.js
index e875ae7289fa69b7f40da4b815cbacfaa6022486..10cf3a115c434c4212f79d0c2056a0785bc39afd 100644
--- a/Source/devtools/front_end/ui/InplaceEditor.js
+++ b/Source/devtools/front_end/ui/InplaceEditor.js
@@ -10,9 +10,14 @@ WebInspector.InplaceEditor = function()
 }
 
 /**
+ * @typedef {{cancel: function(), commit: function(), setWidth: function(number)}}
+ */
+WebInspector.InplaceEditor.Controller;
+
+/**
  * @param {!Element} element
  * @param {!WebInspector.InplaceEditor.Config=} config
- * @return {?{cancel: function(), commit: function(), setWidth: function(number)}}
+ * @return {?WebInspector.InplaceEditor.Controller}
  */
 WebInspector.InplaceEditor.startEditing = function(element, config)
 {
@@ -21,6 +26,28 @@ WebInspector.InplaceEditor.startEditing = function(element, config)
     return WebInspector.InplaceEditor._defaultInstance.startEditing(element, config);
 }
 
+/**
+ * @param {!Element} element
+ * @param {!WebInspector.InplaceEditor.Config=} config
+ * @return {!Promise.<!WebInspector.InplaceEditor.Controller>}
+ */
+WebInspector.InplaceEditor.startMultilineEditing = function(element, config)
+{
+    return self.runtime.instancePromise(WebInspector.InplaceEditor).then(startEditing);
+
+    /**
+     * @param {!Object} inplaceEditor
+     * @return {!WebInspector.InplaceEditor.Controller|!Promise.<!WebInspector.InplaceEditor.Controller>}
+     */
+    function startEditing(inplaceEditor)
+    {
+        var controller = /** @type {!WebInspector.InplaceEditor} */ (inplaceEditor).startEditing(element, config);
+        if (!controller)
+            return Promise.rejectWithError("Editing is already in progress");
+        return controller;
+    }
+}
+
 WebInspector.InplaceEditor.prototype = {
     /**
      * @return {string}
@@ -74,7 +101,7 @@ WebInspector.InplaceEditor.prototype = {
     /**
      * @param {!Element} element
      * @param {!WebInspector.InplaceEditor.Config=} config
-     * @return {?{cancel: function(), commit: function()}}
+     * @return {?WebInspector.InplaceEditor.Controller}
      */
     startEditing: function(element, config)
     {
@@ -190,7 +217,8 @@ WebInspector.InplaceEditor.prototype = {
 
         var handle = {
             cancel: editingCancelled.bind(element),
-            commit: editingCommitted.bind(element)
+            commit: editingCommitted.bind(element),
+            setWidth: function() {}
         };
         this.augmentEditingHandle(editingContext, handle);
         return handle;
@@ -246,6 +274,7 @@ WebInspector.InplaceEditor.Config.prototype = {
      */
     setMultilineOptions: function(initialValue, mode, theme, lineWrapping, smartIndent)
     {
+        this.multiline = true;
         this.initialValue = initialValue;
         this.mode = mode;
         this.theme = theme;