fix(toolbar): md-scroll-shrink conflicts with md-select in toolbar

- find the proper `md-content`, which should be a sibling of the toolbar
- fix scroll shrink breaking if content scrolled too quickly after page load
- improve JSDoc

Fixes #10413. Closes #9871.

Author: Splaktar

src/components/toolbar/toolbar.js

@@ -82,7 +82,7 @@ angular.module('material.components.toolbar', [
  *
  */
 
-function mdToolbarDirective($$rAF, $mdConstant, $mdUtil, $mdTheming, $animate) {
+function mdToolbarDirective($$rAF, $mdConstant, $mdUtil, $mdTheming, $animate, $timeout) {
   var translateY = angular.bind(null, $mdUtil.supplant, 'translate3d(0,{0}px,0)');
 
   return {
@@ -141,16 +141,15 @@ function mdToolbarDirective($$rAF, $mdConstant, $mdUtil, $mdTheming, $animate) {
         scope.$on('$destroy', disableScrollShrink);
 
         /**
-         *
+         * @param {string} shrinkWithScroll value of md-scroll-shrink attribute
          */
         function onChangeScrollShrink(shrinkWithScroll) {
           var closestContent = $mdUtil.getSiblings(element, 'md-content');
 
-          // If we have a content element, fake the call; this might still fail
-          // if the content element isn't a sibling of the toolbar
-
+          // If there are content elements, fake the call using the first content element.
+          // This might still fail if the content element isn't a sibling of the toolbar.
           if (!contentElement && closestContent.length) {
-            onMdContentLoad(null, closestContent);
+            onMdContentLoad(null, closestContent[0]);
           }
 
           // Evaluate the expression
@@ -165,7 +164,8 @@ function mdToolbarDirective($$rAF, $mdConstant, $mdUtil, $mdTheming, $animate) {
         }
 
         /**
-         *
+         * @param {null} $event $mdContentLoaded always has a null event
+         * @param {JQLite} newContentEl JQLite object containing an md-content
          */
         function onMdContentLoad($event, newContentEl) {
           // Toolbar and content must be siblings
@@ -219,7 +219,7 @@ function mdToolbarDirective($$rAF, $mdConstant, $mdUtil, $mdTheming, $animate) {
           contentElement.on('scroll', debouncedContentScroll);
           contentElement.attr('scroll-shrink', 'true');
 
-          $mdUtil.nextTick(updateToolbarHeight, false);
+          $timeout(updateToolbarHeight);
 
           return function disableScrollShrink() {
             contentElement.off('scroll', debouncedContentScroll);

src/core/util/util.js

@@ -603,18 +603,23 @@ function UtilFactory($document, $timeout, $compile, $rootScope, $$mdAnimate, $in
     },
 
     /**
-     * Get an element siblings matching a given tag name
+     * Get an element's siblings matching a given tag name.
      *
-     * @param el Element to start walking the DOM from
-     * @param tagName Tag name to match
+     * @param {JQLite|angular.element|HTMLElement} element Element to start walking the DOM from
+     * @param {string} tagName HTML tag name to match against
+     * @returns {Object[]} JQLite
      */
     getSiblings: function getSiblings(element, tagName) {
       var upperCasedTagName = tagName.toUpperCase();
-      if (element instanceof angular.element) element = element[0];
+      if (element instanceof angular.element) {
+        element = element[0];
+      }
       var siblings = Array.prototype.filter.call(element.parentNode.children, function(node) {
         return element !== node && node.tagName.toUpperCase() === upperCasedTagName;
       });
-      return angular.element(siblings);
+      return siblings.map(function (sibling) {
+        return angular.element(sibling);
+      });
     },
 
     /*

src/core/util/util.spec.js

@@ -679,22 +679,24 @@ describe('util', function() {
       $mdUtil = _$mdUtil_;
     }));
 
-    it('should be able to get the siblings (wihout source element) of a particular node type', function() {
-      var parent = angular.element('<h1>');
-      var element = angular.element('<h2>');
-      var sibling = angular.element('<h2>');
+    it('should be able to get the siblings (without source element) of a particular node type',
+      function () {
+        var parent = angular.element('<h1>');
+        var element = angular.element('<h2>');
+        var sibling = angular.element('<h2>');
 
-      parent.append(element);
-      parent.append(sibling);
+        parent.append(element);
+        parent.append(sibling);
 
-      var result = $mdUtil.getSiblings(element, 'h2');
+        var result = $mdUtil.getSiblings(element, 'h2');
 
-      expect(result).toBeTruthy();
-      expect(result.length).toBe(1);
-      expect(result[0]).toBe(sibling[0]);
+        expect(result).toBeTruthy();
+        expect(result.length).toBe(1);
+        // Get the first sibling and unwrap both jqLite wrappers
+        expect(result[0][0]).toBe(sibling[0]);
 
-      parent.remove();
-    });
+        parent.remove();
+      });
   });
 
   describe('getClosest', function() {