minor fixes

Author: andrewseguin

src/lib/select/_select-theme.scss

@@ -19,7 +19,7 @@
     }
   }
 
-  .mat-select-border {
+  .mat-select-underline {
     background-color: mat-color($foreground, divider);
 
     .mat-select:focus:not(.mat-select-disabled) & {

src/lib/select/select.html

@@ -5,7 +5,7 @@
     <span class="mat-select-value-text">{{ selected?.viewValue }}</span>
   </span>
   <span class="mat-select-arrow"></span>
-  <span class="mat-select-border"></span>
+  <span class="mat-select-underline"></span>
 </div>
 
 <template cdk-connected-overlay [origin]="origin" [open]="panelOpen" hasBackdrop (backdropClick)="close()"

src/lib/select/select.scss

@@ -19,7 +19,6 @@ $mat-select-trigger-font-size: 16px !default;
 
 .mat-select-trigger {
   display: flex;
-  justify-content: space-between;
   align-items: center;
   height: $mat-select-trigger-height;
   min-width: $mat-select-trigger-min-width;
@@ -34,7 +33,7 @@ $mat-select-trigger-font-size: 16px !default;
   }
 }
 
-.mat-select-border {
+.mat-select-underline {
   position: absolute;
   bottom: 0;
   left: 0;
@@ -52,6 +51,7 @@ $mat-select-trigger-font-size: 16px !default;
   position: relative;
   padding: 0 2px;
   transform-origin: left top;
+  flex-grow: 1;
 
   // These values are duplicated from animation code in order to
   // allow placeholders to sometimes float without animating,
@@ -82,6 +82,7 @@ $mat-select-trigger-font-size: 16px !default;
 .mat-select-value {
   position: absolute;
   max-width: calc(100% - #{($mat-select-arrow-size + $mat-select-arrow-margin) * 2});
+  flex-grow: 1;
 
   // Firefox and some versions of IE incorrectly keep absolutely
   // positioned children of flex containers in the flex flow when calculating