Add proper @return tags to functions' PHPDoc comments

Reviewed. Looks good.

Also reviewed, think this is RTBC.

1. +++ b/core/lib/Drupal/Core/Ajax/CssCommand.php
   @@ -61,6 +61,9 @@ public function __construct($selector, array $css = array()) {
   +   *
   +   * @return array
   +   *   The property/value pair.
   

   This returns $this

2. +++ b/core/lib/Drupal/Core/Asset/CssOptimizer.php
   @@ -220,6 +220,9 @@ protected function processCss($contents, $optimize = FALSE) {
   +   *
   +   * @return string
   +   *   The prefixed path.
   

   Afaics this returns the file path.

+++ b/core/lib/Drupal/Core/Ajax/CssCommand.php
@@ -61,6 +61,9 @@ public function __construct($selector, array $css = array()) {
+   *   The property/value pair.

Incorrect description. Also, when using @return $this, the description may be left out completely.

Rerolled the patch with proper documentation.

Add missing \ in previous patch

+++ b/core/lib/Drupal/Core/Ajax/CssCommand.php
@@ -61,6 +61,9 @@ public function __construct($selector, array $css = array()) {
+   * @return \Drupal\Core\Ajax\CommandInterface
+   *   The called command.

This must be @return $this.

With $this it is :)

+++ b/core/lib/Drupal/Core/Ajax/CssCommand.php
@@ -61,6 +61,9 @@ public function __construct($selector, array $css = array()) {
+   * @return $this
+   *   The called command.

No description is needed, because @return $this can only mean one thing (the object on which the method was called). See the handbook for more information (and we copied it from PhpDoc again).

@Xano Thanks for clearing this up and the review, I wasn't aware of the special @return $this.

Updated in the patch, removed the description after @return $this.

Looks good. Thanks!

I think that's right, but sending to jhodgdon to confirm.

I can confirm that the formatting of the documentation added lines is correct. I have not reviewed them for accuracy, but others have done that. +1.

Thanks @jhodgdon for confirming. This issue only improves documentation, so per https://www.drupal.org/core/beta-changes, this can be completed any time during the Drupal 8 beta phase.

I checked over both methods' return values and the documentation appears accurate. (Though, yowza at CssOptimizer::loadNestedFile() generally, but improving the inline docs isn't in scope here.)

Committed and pushed to 8.0.x. Thanks everyone!