DevTools: Add JSDoc for static methods, fix JSDoc types and induced errors

Source/devtools/front_end/timeline/TimelineFlameChart.js

 /*
  * Copyright (C) 2014 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 253 matching lines @@
      * @param {number} entryIndex
      * @return {boolean}
      */
     canJumpToEntry: function(entryIndex)
     {
         return false;
     },
 
     /**
      * @param {number} entryIndex
-     * @return {!string}
+     * @return {string}
      */
     entryColor: function(entryIndex)
     {
         var record = this._records[entryIndex];
         if (record === this._cpuThreadRecord || record === this._gpuThreadRecord)
             return "#555";
 
         if (record.type() === WebInspector.TimelineModel.RecordType.JSFrame)
             return WebInspector.TimelineFlameChartDataProvider.jsFrameColorGenerator().colorForID(record.data()["functionName"]);
 
@@ skipping 103 matching lines @@
     /**
      * @return {number}
      */
     paddingLeft: function()
     {
         return 0;
     },
 
     /**
      * @param {number} entryIndex
-     * @return {!string}
+     * @return {string}
      */
     textColor: function(entryIndex)
     {
         return "white";
     },
 
     /**
      * @param {number} entryIndex
      * @return {?WebInspector.TimelineSelection}
      */
@@ skipping 199 matching lines @@
      * @param {number} entryIndex
      * @return {boolean}
      */
     canJumpToEntry: function(entryIndex)
     {
         return false;
     },
 
     /**
      * @param {number} entryIndex
-     * @return {!string}
+     * @return {string}
      */
     entryColor: function(entryIndex)
     {
         var event = this._entryEvents[entryIndex];
         if (!event)
             return "#555";
         var style = WebInspector.TimelineUIUtils.styleForTimelineEvent(event.name);
         return style.category.fillColorStop1;
     },
 
@@ skipping 77 matching lines @@
     /**
      * @return {number}
      */
     paddingLeft: function()
     {
         return 0;
     },
 
     /**
      * @param {number} entryIndex
-     * @return {!string}
+     * @return {string}
      */
     textColor: function(entryIndex)
     {
         return "white";
     },
 
     /**
      * @param {string} title
      */
     _appendHeaderRecord: function(title)
@@ skipping 244 matching lines @@
      * @param {number} entryIndex
      * @return {?WebInspector.TimelineSelection}
      */
     createSelection: function(entryIndex) { },
     /**
      * @param {?WebInspector.TimelineSelection} selection
      * @return {number}
      */
     entryIndexForSelection: function(selection) { }
 }