Implement select element list box with shadow DOM.

Source/WebCore/css/html.css

Index: Source/WebCore/css/html.css
diff --git a/Source/WebCore/css/html.css b/Source/WebCore/css/html.css
index ddbe56c52d38653bb2fc9620f6872ac63daaab12..86a1c0be7506f69de69e2e06c1dfb32f512f9f35 100644
--- a/Source/WebCore/css/html.css
+++ b/Source/WebCore/css/html.css
@@ -937,31 +937,48 @@ select {
     cursor: default;
 }
 
-select[size],
-select[multiple],
-select[size][multiple] {
-    -webkit-appearance: listbox;
+select:-webkit-any([size]:not([size="0"]):not([size="1"]), [multiple]) {
+    -webkit-appearance: none;
     -webkit-align-items: flex-start;
     border: 1px inset gray;
     border-radius: initial;
     white-space: initial;
-}
-
-select[size="0"],
-select[size="1"] {
-    -webkit-appearance: menulist;
-    -webkit-align-items: center;
-    border: 1px solid;
-    border-radius: 5px;
-    white-space: pre;
+    overflow-x: hidden;
+    overflow-y: scroll;
+    vertical-align: text-bottom;
+    -webkit-user-select: none;
+    white-space: nowrap;
 }
 
 optgroup {
     font-weight: bolder;
+    display: block;
 }
 
 option {
     font-weight: normal;
+    display: block;
+    padding: 0 2px 1px 2px;
+}
+
+optgroup option {
+    padding-left: calc(2px + 1.3em);
+}
+
+select option:checked {
+    background-color: activelistboxselection;
+}
+
+select:not(:disabled) option:checked:not(:disabled) {
+    color: activelistboxselectiontext;
+}
+
+select:not(:focus) option:checked {
+    background-color: inactivelistboxselection;
+}
+
+select:not(:focus):not(:disabled) option:checked:not(:disabled) {
+    color: inactivelistboxselectiontext;
 }
 
 output {