fix(icon): Change iconSize param to viewBoxSize.

Updates code and docs.
Also removes redundant function names.

Fixes #1679

Closes #3123

BREAKING CHANGE: The API has changed for `md-icon` - `iconSize` has been
changed to `viewBoxSize`

src/components/icon/iconService.js

@@ -74,8 +74,8 @@
     * @param {string} id Icon name/id used to register the icon
     * @param {string} url specifies the external location for the data file. Used internally by `$http` to load the
     * data or as part of the lookup in `$templateCache` if pre-loading was configured.
-    * @param {string=} iconSize Number indicating the width and height of the icons in the set. All icons
-    * in the icon set must be the same size. Default size is 24.
+    * @param {number=} viewBoxSize Sets the width and height the icon's viewBox.
+    * It is ignored for icons with an existing viewBox. Default size is 24.
     *
     * @returns {obj} an `$mdIconProvider` reference; used to support method call chains for the API
     *
@@ -104,8 +104,9 @@
     * @param {string} id Icon name/id used to register the iconset
     * @param {string} url specifies the external location for the data file. Used internally by `$http` to load the
     * data or as part of the lookup in `$templateCache` if pre-loading was configured.
-    * @param {string=} iconSize Number indicating the width and height of the icons in the set. All icons
-    * in the icon set must be the same size. Default size is 24.
+    * @param {number=} viewBoxSize Sets the width and height of the viewBox of all icons in the set. 
+    * It is ignored for icons with an existing viewBox. All icons in the icon set should be the same size.
+    * Default value is 24.
     *
     * @returns {obj} an `$mdIconProvider` reference; used to support method call chains for the API
     *
@@ -133,8 +134,9 @@
     *
     * @param {string} url specifies the external location for the data file. Used internally by `$http` to load the
     * data or as part of the lookup in `$templateCache` if pre-loading was configured.
-    * @param {string=} iconSize Number indicating the width and height of the icons in the set. All icons
-    * in the icon set must be the same size. Default size is 24.
+    * @param {number=} viewBoxSize Sets the width and height of the viewBox of all icons in the set. 
+    * It is ignored for icons with an existing viewBox. All icons in the icon set should be the same size.
+    * Default value is 24.
     *
     * @returns {obj} an `$mdIconProvider` reference; used to support method call chains for the API
     *
@@ -184,15 +186,14 @@
 
    /**
     * @ngdoc method
-    * @name $mdIconProvider#defaultIconSize
+    * @name $mdIconProvider#defaultViewBoxSize
     *
     * @description
     * While `<md-icon />` markup can also be style with sizing CSS, this method configures
     * the default width **and** height used for all icons; unless overridden by specific CSS.
     * The default sizing is (24px, 24px).
-    *
-    * @param {string} iconSize Number indicating the width and height of the icons in the set. All icons
-    * in the icon set must be the same size. Default size is 24.
+    * @param {number=} viewBoxSize Sets the width and height of the viewBox for an icon or an icon set.
+    * All icons in a set should be the same size. The default value is 24.
     *
     * @returns {obj} an `$mdIconProvider` reference; used to support method call chains for the API
     *
@@ -203,43 +204,50 @@
     *     // Configure URLs for icons specified by [set:]id.
     *
     *     $mdIconProvider
-    *          .defaultIconSize(36)   // Register a default icon size (width == height)
+    *          .defaultViewBoxSize(36)   // Register a default icon size (width == height)
     *   });
     * </hljs>
     *
     */
 
  var config = {
-   defaultIconSize: 24,
+   defaultViewBoxSize: 24,
    defaultFontSet: 'material-icons',
    fontSets : [ ]
  };
 
  function MdIconProvider() { }
 
  MdIconProvider.prototype = {
-
-   icon : function icon(id, url, iconSize) {
+   icon : function (id, url, viewBoxSize) {
      if ( id.indexOf(':') == -1 ) id = '$default:' + id;
 
-     config[id] = new ConfigurationItem(url, iconSize );
+     config[id] = new ConfigurationItem(url, viewBoxSize );
      return this;
    },
-   iconSet : function iconSet(id, url, iconSize) {
-     config[id] = new ConfigurationItem(url, iconSize );
+
+   iconSet : function (id, url, viewBoxSize) {
+     config[id] = new ConfigurationItem(url, viewBoxSize );
      return this;
    },
-   defaultIconSet : function defaultIconSet(url, iconSize) {
+
+   defaultIconSet : function (url, viewBoxSize) {
      var setName = '$default';
 
      if ( !config[setName] ) {
-       config[setName] = new ConfigurationItem(url, iconSize );
+       config[setName] = new ConfigurationItem(url, viewBoxSize );
      }
 
-     config[setName].iconSize = iconSize || config.defaultIconSize;
+     config[setName].viewBoxSize = viewBoxSize || config.defaultViewBoxSize;
+
      return this;
    },
 
+   defaultViewBoxSize : function (viewBoxSize) {
+     config.defaultViewBoxSize = viewBoxSize;
+     return this;
+   },
+
    /**
     * Register an alias name associated with a font-icon library style ;
     */
@@ -312,9 +320,9 @@
     *  Configuration item stored in the Icon registry; used for lookups
     *  to load if not already cached in the `loaded` cache
     */
-   function ConfigurationItem(url, iconSize) {
+   function ConfigurationItem(url, viewBoxSize) {
      this.url = url;
-     this.iconSize = iconSize || config.defaultIconSize;
+     this.viewBoxSize = viewBoxSize || config.defaultViewBoxSize;
    }
 
  /**
@@ -512,13 +520,13 @@
     *  loaded iconCache store.
     */
    function prepareAndStyle() {
-     var iconSize = this.config ? this.config.iconSize : config.defaultIconSize;
+     var viewBoxSize = this.config ? this.config.viewBoxSize : config.defaultViewBoxSize;
          angular.forEach({
            'fit'   : '',
            'height': '100%',
            'width' : '100%',
            'preserveAspectRatio': 'xMidYMid meet',
-           'viewBox' : this.element.getAttribute('viewBox') || ('0 0 ' + iconSize + ' ' + iconSize)
+           'viewBox' : this.element.getAttribute('viewBox') || ('0 0 ' + viewBoxSize + ' ' + viewBoxSize)
          }, function(val, attr) {
            this.element.setAttribute(attr, val);
          }, this);