fix(tabs): fixes tab math to address issues when used within dialog

closes #7048. Closes #7118.

src/components/tabs/js/tabsController.js

@@ -545,11 +545,13 @@ function MdTabsController ($scope, $element, $window, $mdConstant, $mdTabInkRipp
   function updatePagingWidth() {
     var width = 1;
     angular.forEach(getElements().dummies, function (element) {
-      // uses `getBoundingClientRect().width` rather than `offsetWidth` to include decimal values
-      // when calculating the total width
-      width += Math.ceil(element.getBoundingClientRect().width);
+      //-- Uses the larger value between `getBoundingClientRect().width` and `offsetWidth`.  This
+      //   prevents `offsetWidth` value from being rounded down and causing wrapping issues, but
+      //   also handles scenarios where `getBoundingClientRect()` is inaccurate (ie. tabs inside
+      //   of a dialog)
+      width += Math.max(element.offsetWidth, element.getBoundingClientRect().width);
     });
-    angular.element(elements.paging).css('width', width + 'px');
+    angular.element(elements.paging).css('width', Math.ceil(width) + 'px');
   }
 
   function getMaxTabWidth () {