Upgrade/Install: Update 'show details' button change.

Add a up/down arrow for visual affordance about the purpose of the button link; change button text from "Show details" to "More details".

Props krupajnanda, subrataemfluence, audrasjb, afercia, nrqsnchz, joedolson.
Fixes #44714.

git-svn-id: https://develop.svn.wordpress.org/trunk@56027 602fd350-edb4-49c9-b593-d223f7449a82

src/wp-admin/css/common.css

@@ -553,6 +553,14 @@ code {
 	margin-left: 0;
 }
 
+.js-update-details-toggle .dashicons {
+	text-decoration: none;
+}
+
+.js-update-details-toggle[aria-expanded="true"] .dashicons::before {
+	content: "\f142";
+}
+
 .no-js .widefat thead .check-column input,
 .no-js .widefat tfoot .check-column input {
 	display: none;

src/wp-admin/includes/class-bulk-upgrader-skin.php

@@ -131,7 +131,7 @@ public function before( $title = '' ) {
 		$this->in_loop = true;
 		printf( '<h2>' . $this->upgrader->strings['skin_before_update_header'] . ' <span class="spinner waiting-' . $this->upgrader->update_current . '"></span></h2>', $title, $this->upgrader->update_current, $this->upgrader->update_count );
 		echo '<script type="text/javascript">jQuery(\'.waiting-' . esc_js( $this->upgrader->update_current ) . '\').css("display", "inline-block");</script>';
-		// This progress messages div gets moved via JavaScript when clicking on "Show details.".
+		// This progress messages div gets moved via JavaScript when clicking on "More details.".
 		echo '<div class="update-messages hide-if-js" id="progress-' . esc_attr( $this->upgrader->update_current ) . '"><p>';
 		$this->flush_output();
 	}
@@ -154,7 +154,7 @@ public function after( $title = '' ) {
 			if ( ! $this->error ) {
 				echo '<div class="updated js-update-details" data-update-details="progress-' . esc_attr( $this->upgrader->update_current ) . '">' .
 					'<p>' . sprintf( $this->upgrader->strings['skin_update_successful'], $title ) .
-					' <button type="button" class="hide-if-no-js button-link js-update-details-toggle" aria-expanded="false">' . __( 'Show details.' ) . '</button>' .
+					' <button type="button" class="hide-if-no-js button-link js-update-details-toggle" aria-expanded="false">' . __( 'More details.' ) . '<span class="dashicons dashicons-arrow-down" aria-hidden="true"></span></button>' .
 					'</p></div>';
 			}