Fix focus change for updated slider

Author: jwshinjwshin

src/lib/slider/slider.spec.ts

@@ -141,6 +141,17 @@ describe('MdSlider without forms', () => {
       expect(sliderNativeElement.classList).not.toContain('mat-slider-sliding');
     });
 
+    it('should remove focus after the slider is updated', () => {
+      spyOn(sliderNativeElement, 'blur');
+
+      expect(sliderNativeElement.blur).not.toHaveBeenCalled();
+
+      dispatchClickEventSequence(sliderNativeElement, 0.39);
+      fixture.detectChanges();
+
+      expect(sliderNativeElement.blur).toHaveBeenCalled();
+    });
+
     it('should have thumb gap when at min value', () => {
       expect(trackFillElement.style.transform).toContain('translateX(-7px)');
     });

src/lib/slider/slider.ts

@@ -445,6 +445,7 @@ export class MdSlider extends _MdSliderMixinBase
       this._emitInputEvent();
       this._emitChangeEvent();
     }
+    this._elementRef.nativeElement.blur();
   }
 
   _onSlide(event: HammerInput) {