Polymer 2: Some minor CSS fixes

Change-Id: I1bb0cdc47d49fceebaae551387877fc0f61120a4

polygerrit-ui/app/elements/change/gr-change-view/gr-change-view.html

@@ -235,6 +235,7 @@ limitations under the License.
         --paper-tabs-selection-bar-color: var(--link-color);
       }
       paper-tab {
+        box-sizing: border-box;
         max-width: 15rem;
         --paper-tab-ink: var(--link-color);
       }

polygerrit-ui/app/elements/change/gr-label-score-row/gr-label-score-row.html

@@ -61,7 +61,7 @@ limitations under the License.
           background-color: var(--button-background-color, var(--table-header-background-color));
           color: var(--primary-text-color);
           padding: .2em .85em;
-          @apply(--vote-chip-styles);
+          @apply --vote-chip-styles;
         }
       }
       gr-button.iron-selected.max {

polygerrit-ui/app/elements/shared/gr-autocomplete/gr-autocomplete.html

@@ -29,7 +29,7 @@ limitations under the License.
         display: none;
       }
       .searchIcon.showSearchIcon {
-        display: initial;
+        display: inline-block;
       }
       iron-icon {
         margin: 0 .25em;

polygerrit-ui/app/elements/shared/gr-button/gr-button.html

@@ -94,7 +94,9 @@ limitations under the License.
       }
 
       /* Styles for the optional down arrow */
-      :host:not([down-arrow]) .downArrow {display: none; }
+      :host(:not([down-arrow])) .downArrow {
+        display: none;
+      }
       :host([down-arrow]) .downArrow {
         border-top: .36em solid #ccc;
         border-left: .36em solid transparent;

polygerrit-ui/app/elements/shared/gr-change-status/gr-change-status.html

@@ -68,7 +68,7 @@ limitations under the License.
         background-color: transparent;
         padding: .1em;
       }
-      :host:not([flat]) .chip {
+      :host(:not([flat])) .chip {
         color: white;
       }
     </style>