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

Source/devtools/front_end/elements/Spectrum.js

 /*
  * Copyright (C) 2011 Brian Grinstead All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  *
  * 1.  Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
  * 2.  Redistributions in binary form must reproduce the above copyright
@@ skipping 280 matching lines @@
         var slideY = this.slideHeight - ((h * this.slideHeight) + this.slideHelperHeight);
         this.slideHelper.style.top = slideY + "px";
 
         this._alphaElement.value = this._hsv[3] * 100;
     },
 
     _updateUI: function()
     {
         this._updateHelperLocations();
 
-        this._draggerElement.style.backgroundColor = WebInspector.Color.fromHSVA([this._hsv[0], 1, 1, 1]).toString(WebInspector.Color.Format.RGB);
-        this._swatchInnerElement.style.backgroundColor = this.color().toString(WebInspector.Color.Format.RGBA);
+        this._draggerElement.style.backgroundColor = /** @type {string} */ (WebInspector.Color.fromHSVA([this._hsv[0], 1, 1, 1]).toString(WebInspector.Color.Format.RGB));
+        this._swatchInnerElement.style.backgroundColor = /** @type {string} */ (this.color().toString(WebInspector.Color.Format.RGBA));
 
         this._alphaElement.value = this._hsv[3] * 100;
     },
 
     wasShown: function()
     {
         this.slideHeight = this._sliderElement.offsetHeight;
         this.dragWidth = this._draggerElement.offsetWidth;
         this.dragHeight = this._draggerElement.offsetHeight;
         this._dragHelperElementHeight = this._dragHelperElement.offsetHeight / 2;
@@ skipping 131 matching lines @@
 
 WebInspector.ColorSwatch.prototype = {
     /**
      * @param {string} colorString
      */
     setColorString: function(colorString)
     {
         this._swatchInnerElement.style.backgroundColor = colorString;
     }
 }