Fix test injection issues.

Author: crisbeto

src/lib/dialog/dialog.spec.ts

@@ -437,7 +437,8 @@ describe('MdDialog with a parent MdDialog', () => {
         {provide: OverlayContainer, useFactory: () => {
           overlayContainerElement = document.createElement('div');
           return {getContainerElement: () => overlayContainerElement};
-        }}
+        }},
+        {provide: Location, useClass: SpyLocation}
       ],
     });