Document that fade-out duration can't be modified through the speedFa…

…ctor

src/lib/core/ripple/ripple-renderer.ts

@@ -1,8 +1,10 @@
 import {ElementRef, NgZone} from '@angular/core';
 import {ViewportRuler} from '../overlay/position/viewport-ruler';
 
-
+/** Fade-in speed in pixels per second. Can be modified with the speedFactor option. */
 export const RIPPLE_SPEED_PX_PER_SECOND = 170;
+
+/** Fade-out speed for the ripples in milliseconds. This can't be modified by the speedFactor. */
 export const RIPPLE_FADE_OUT_DURATION = 600;
 
 /**

src/lib/core/ripple/ripple.ts

@@ -53,6 +53,7 @@ export class MdRipple implements OnChanges, OnDestroy {
   /**
    * If set, the normal duration of ripple animations is divided by this value. For example,
    * setting it to 0.5 will cause the animations to take twice as long.
+   * A changed speedFactor will not modify the fade-out duration of the ripples.
    */
   @Input('mdRippleSpeedFactor') speedFactor: number = 1;