fix(mdChips): Autocomplete styling is incorrect.

The chips autocomplete had unnecessary styling and the default
autocomplete directive does not add the `md-input` class to it's
input, so it did not look correct.

Also fixes issue with md-chip readonly padding styles.

Fixes #4600. Closes #4621.

src/components/chips/chips.scss

@@ -1,6 +1,7 @@
 $chip-font-size: rem(1.6) !default;
 $chip-height: rem(3.2) !default;
 $chip-padding: 0 rem(1.2) 0 rem(1.2) !default;
+$chip-input-padding: 0 !default;
 $chip-remove-padding-right: rem(2.2) !default;
 $chip-remove-line-height: rem(2.2) !default;
 $chip-margin: rem(0.8) rem(0.8) 0 0 !default;
@@ -62,7 +63,7 @@ $contact-chip-name-width: rem(12) !default;
   &:not(.md-readonly) {
     cursor: text;
 
-    .md-chip {
+    .md-chip:not(.md-readonly) {
       padding-right: $chip-remove-padding-right;
     }
   }
@@ -122,7 +123,7 @@ $contact-chip-name-width: rem(12) !default;
     display: block;
     line-height: $chip-height;
     margin: $chip-margin;
-    padding: $chip-padding;
+    padding: $chip-input-padding;
     float: left;
     input {
       &:not([type]),&[type="email"],&[type="number"],&[type="tel"],&[type="url"],&[type="text"] {

src/components/chips/js/chipsDirective.js

@@ -115,6 +115,7 @@
 
   var CHIP_INPUT_TEMPLATE = '\
         <input\
+            class="md-input"\
             tabindex="0"\
             placeholder="{{$mdChipsCtrl.getPlaceholder()}}"\
             aria-label="{{$mdChipsCtrl.getPlaceholder()}}"\
@@ -232,7 +233,6 @@
        * Configures controller and transcludes.
        */
       return function postLink(scope, element, attrs, controllers) {
-
         $mdUtil.initOptionalProperties(scope, attr);
 
         $mdTheming(element);
@@ -280,6 +280,13 @@
               }
             });
           }
+
+          // At the next tick, if we find an input, make sure it has the md-input class
+          $mdUtil.nextTick(function() {
+            var input = element.find('input');
+
+            input && input.toggleClass('md-input', true);
+          });
         }
 
         // Compile with the parent's scope and prepend any static chips to the wrapper.