addressed comments

Author: mmalerba

src/lib/input/autosize.spec.ts

@@ -218,14 +218,14 @@ describe('MdTextareaAutosize', () => {
     const fixtureWithForms = TestBed.createComponent(AutosizeTextareaInATab);
     fixtureWithForms.detectChanges();
     textarea = fixtureWithForms.nativeElement.querySelector('textarea');
-    expect(textarea.getBoundingClientRect().height).toBeGreaterThan(0);
+    expect(textarea.getBoundingClientRect().height).toBeGreaterThan(1);
   });
 
   it('should work in a step', () => {
     const fixtureWithForms = TestBed.createComponent(AutosizeTextareaInAStep);
     fixtureWithForms.detectChanges();
     textarea = fixtureWithForms.nativeElement.querySelector('textarea');
-    expect(textarea.getBoundingClientRect().height).toBeGreaterThan(0);
+    expect(textarea.getBoundingClientRect().height).toBeGreaterThan(1);
   });
 });
 

src/lib/input/autosize.ts

@@ -136,7 +136,9 @@ export class MdTextareaAutosize implements AfterViewInit, DoCheck {
   }
 
   ngDoCheck() {
-    this.resizeToFitContent();
+    if (this._platform.isBrowser) {
+      this.resizeToFitContent();
+    }
   }
 
   /** Resize the textarea to fit its content. */