fix: resolve unit test failures

Author: crisbeto

src/examples/select-header/select-header-example.html

@@ -1,4 +1,4 @@
-<md-select placeholder="Favorite food" [(ngModel)]="currentDrink" name="food" #select="mdSelect">
+<md-select placeholder="Favorite food" [(ngModel)]="selectedValue" name="food" #select="mdSelect">
   <md-select-header>
     <input type="search" [(ngModel)]="searchString" role="combobox" [attr.aria-owns]="select.panelId"
       (ngModelChange)="filterFoods()" placeholder="Search for food"/>

src/lib/select/select.spec.ts

@@ -31,7 +31,7 @@ import {
 } from '../core/placeholder/placeholder-options';
 
 
-fdescribe('MdSelect', () => {
+describe('MdSelect', () => {
   let overlayContainerElement: HTMLElement;
   let dir: {value: 'ltr'|'rtl'};
   let scrolledSubject = new Subject();
@@ -983,7 +983,7 @@ fdescribe('MdSelect', () => {
         trigger.click();
         groupFixture.detectChanges();
 
-        const scrollContainer = document.querySelector('.cdk-overlay-pane .mat-select-panel');
+        const scrollContainer = document.querySelector('.cdk-overlay-pane .mat-select-content');
 
         // The selected option should be scrolled to the center of the panel.
         // This will be its original offset from the scrollTop - half the panel height + half the

src/lib/select/select.ts

@@ -802,9 +802,8 @@ export class MdSelect extends _MdSelectMixinBase implements AfterContentInit, On
       // we must only adjust for the height difference between the option element
       // and the trigger element, then multiply it by -1 to ensure the panel moves
       // in the correct direction up the page.
-      this._offsetY = (SELECT_ITEM_HEIGHT - SELECT_TRIGGER_HEIGHT) / 2 * -1;
-      // this._offsetY = (SELECT_OPTION_HEIGHT - SELECT_TRIGGER_HEIGHT) / 2 * -1 -
-      //     (this.header ? SELECT_OPTION_HEIGHT : 0);
+      this._offsetY = (SELECT_ITEM_HEIGHT - SELECT_TRIGGER_HEIGHT) / 2 * -1 -
+          (this.header ? SELECT_ITEM_HEIGHT : 0);
     }
 
     this._checkOverlayWithinViewport(maxScroll);
@@ -958,7 +957,6 @@ export class MdSelect extends _MdSelectMixinBase implements AfterContentInit, On
     const panelHeightTop = Math.abs(this._offsetY);
     const totalPanelHeight =
         Math.min(this._getItemCount() * SELECT_ITEM_HEIGHT, SELECT_PANEL_MAX_HEIGHT);
-        // Math.min(this.options.length * SELECT_OPTION_HEIGHT, SELECT_PANEL_MAX_HEIGHT);
     const panelHeightBottom = totalPanelHeight - panelHeightTop - triggerRect.height;
 
     if (panelHeightBottom > bottomSpaceAvailable) {