diff --git a/core/lib/Drupal/Core/Condition/ConditionAccessResolverTrait.php b/core/lib/Drupal/Core/Condition/ConditionAccessResolverTrait.php
index 9f16d09..65990da 100644
--- a/core/lib/Drupal/Core/Condition/ConditionAccessResolverTrait.php
+++ b/core/lib/Drupal/Core/Condition/ConditionAccessResolverTrait.php
@@ -35,17 +35,17 @@ protected function resolveConditions($conditions, $condition_logic) {
         $pass = FALSE;
       }
 
-      // If a condition fails and all conditions were required, deny access.
+      // If a condition fails and all conditions were needed, deny access.
       if (!$pass && $condition_logic == 'and') {
         return FALSE;
       }
-      // If a condition passes and one condition was required, grant access.
+      // If a condition passes and only one condition was needed, grant access.
       elseif ($pass && $condition_logic == 'or') {
         return TRUE;
       }
     }
 
-    // If no conditions passed and one condition was required, deny access.
+    // If no conditions passed and one condition was needed, deny access.
     return $condition_logic == 'and';
   }
 
diff --git a/core/lib/Drupal/Core/Condition/ConditionPluginBag.php b/core/lib/Drupal/Core/Condition/ConditionPluginBag.php
index acb0fce..394bebf 100644
--- a/core/lib/Drupal/Core/Condition/ConditionPluginBag.php
+++ b/core/lib/Drupal/Core/Condition/ConditionPluginBag.php
@@ -7,6 +7,7 @@
 
 namespace Drupal\Core\Condition;
 
+use Drupal\Component\Plugin\Context\ContextInterface;
 use Drupal\Core\Plugin\DefaultPluginBag;
 
 /**
@@ -15,6 +16,13 @@
 class ConditionPluginBag extends DefaultPluginBag {
 
   /**
+   * An array of collected contexts for conditions.
+   *
+   * @var \Drupal\Component\Plugin\Context\ContextInterface[]
+   */
+  protected $conditionContexts = array();
+
+  /**
    * {@inheritdoc}
    *
    * @return \Drupal\Core\Condition\ConditionInterface
@@ -40,4 +48,29 @@ public function getConfiguration() {
     return $configuration;
   }
 
+  /**
+   * Sets the condition context for a given name.
+   *
+   * @param string $name
+   *   The name of the context.
+   * @param \Drupal\Component\Plugin\Context\ContextInterface $context
+   *   The context to add.
+   *
+   * @return $this
+   */
+  public function addContext($name, ContextInterface $context) {
+    $this->conditionContexts[$name] = $context;
+    return $this;
+  }
+
+  /**
+   * Gets the values for all defined contexts.
+   *
+   * @return \Drupal\Component\Plugin\Context\ContextInterface[]
+   *   An array of set contexts, keyed by context name.
+   */
+  public function getConditionContexts() {
+    return $this->conditionContexts;
+  }
+
 }
diff --git a/core/modules/block/src/BlockBase.php b/core/modules/block/src/BlockBase.php
index 33ddd39..d1eb821 100644
--- a/core/modules/block/src/BlockBase.php
+++ b/core/modules/block/src/BlockBase.php
@@ -7,10 +7,8 @@
 
 namespace Drupal\block;
 
-use Drupal\block\Event\BlockContextEvent;
+use Drupal\block\Event\BlockConditionContextEvent;
 use Drupal\block\Event\BlockEvents;
-use Drupal\Component\Plugin\ConfigurablePluginInterface;
-use Drupal\Component\Plugin\Context\ContextInterface;
 use Drupal\Component\Plugin\ContextAwarePluginInterface;
 use Drupal\Core\Condition\ConditionAccessResolverTrait;
 use Drupal\Core\Condition\ConditionPluginBag;
@@ -51,13 +49,6 @@
   protected $conditionPluginManager;
 
   /**
-   * An array of collected contexts for conditions.
-   *
-   * @var \Drupal\Component\Plugin\Context\ContextInterface[]
-   */
-  protected $conditionContexts = array();
-
-  /**
    * {@inheritdoc}
    */
   public function label() {
@@ -164,7 +155,7 @@ public function access(AccountInterface $account) {
         $this->contextHandler()->applyContextMapping($condition, $contexts, $mappings[$condition_id]);
       }
     }
-    if ($this->resolveConditions($conditions, 'and', $this->getConditionContexts(), $mappings) === FALSE) {
+    if ($this->resolveConditions($conditions, 'and', $contexts, $mappings) === FALSE) {
       return FALSE;
     }
     return $this->blockAccess($account);
@@ -177,18 +168,9 @@ public function access(AccountInterface $account) {
    *   An array of set contexts, keyed by context name.
    */
   protected function getConditionContexts() {
-    if (!$this->conditionContexts) {
-      $this->eventDispatcher()->dispatch(BlockEvents::BLOCK_CONTEXT, new BlockContextEvent($this));
-    }
-    return $this->conditionContexts;
-  }
-
-  /**
-   * {@inheritdoc}
-   */
-  public function addContext($name, ContextInterface $context) {
-    $this->conditionContexts[$name] = $context;
-    return $this;
+    $conditions = $this->getVisibilityConditions();
+    $this->eventDispatcher()->dispatch(BlockEvents::CONDITION_CONTEXT, new BlockConditionContextEvent($conditions));
+    return $conditions->getConditionContexts();
   }
 
   /**
diff --git a/core/modules/block/src/BlockPluginInterface.php b/core/modules/block/src/BlockPluginInterface.php
index 37ea357..64fd12f 100644
--- a/core/modules/block/src/BlockPluginInterface.php
+++ b/core/modules/block/src/BlockPluginInterface.php
@@ -172,16 +172,4 @@ public function getVisibilityCondition($instance_id);
    */
   public function setVisibilityConfig($instance_id, array $configuration);
 
-  /**
-   * Sets the condition context for a given name.
-   *
-   * @param string $name
-   *   The name of the context.
-   * @param \Drupal\Component\Plugin\Context\ContextInterface $context
-   *   The context to add.
-   *
-   * @return $this
-   */
-  public function addContext($name, ContextInterface $context);
-
 }
diff --git a/core/modules/block/src/Event/BlockConditionContextEvent.php b/core/modules/block/src/Event/BlockConditionContextEvent.php
new file mode 100644
index 0000000..a290ae6
--- /dev/null
+++ b/core/modules/block/src/Event/BlockConditionContextEvent.php
@@ -0,0 +1,39 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\block\Event\BlockContextEvent.
+ */
+
+namespace Drupal\block\Event;
+
+use Drupal\Core\Condition\ConditionPluginBag;
+use Symfony\Component\EventDispatcher\Event;
+
+/**
+ * Wraps block conditions in order for event subscribers to add context.
+ *
+ * @see \Drupal\block\Event\BlockEvents::CONDITION_CONTEXT
+ */
+class BlockConditionContextEvent extends Event {
+
+  /**
+   * @var \Drupal\Core\Condition\ConditionPluginBag
+   */
+  protected $conditions;
+
+  /**
+   * @param \Drupal\Core\Condition\ConditionPluginBag $conditions
+   */
+  public function __construct(ConditionPluginBag $conditions) {
+    $this->conditions = $conditions;
+  }
+
+  /**
+   * @return \Drupal\block\BlockPluginInterface
+   */
+  public function getConditions() {
+    return $this->conditions;
+  }
+
+}
diff --git a/core/modules/block/src/Event/BlockContextEvent.php b/core/modules/block/src/Event/BlockContextEvent.php
deleted file mode 100644
index 70a5f4f..0000000
--- a/core/modules/block/src/Event/BlockContextEvent.php
+++ /dev/null
@@ -1,39 +0,0 @@
-<?php
-
-/**
- * @file
- * Contains \Drupal\block\Event\BlockContextEvent.
- */
-
-namespace Drupal\block\Event;
-
-use Drupal\block\BlockPluginInterface;
-use Symfony\Component\EventDispatcher\Event;
-
-/**
- * Wraps a block in order for event subscribers to add context.
- *
- * @see \Drupal\block\Event\BlockEvents::BLOCK_CONTEXT
- */
-class BlockContextEvent extends Event {
-
-  /**
-   * @var \Drupal\block\BlockPluginInterface
-   */
-  protected $block;
-
-  /**
-   * @param \Drupal\block\BlockPluginInterface $block
-   */
-  public function __construct(BlockPluginInterface $block) {
-    $this->block = $block;
-  }
-
-  /**
-   * @return \Drupal\block\BlockPluginInterface
-   */
-  public function getBlock() {
-    return $this->block;
-  }
-
-}
diff --git a/core/modules/block/src/Event/BlockEvents.php b/core/modules/block/src/Event/BlockEvents.php
index 88dd588..070eb6c 100644
--- a/core/modules/block/src/Event/BlockEvents.php
+++ b/core/modules/block/src/Event/BlockEvents.php
@@ -13,11 +13,11 @@
 final class BlockEvents {
 
   /**
-   * Name of the event when gathering context for a block plugin.
+   * Name of the event when gathering condition context for a block plugin.
    *
    * @see \Drupal\block\BlockBase::getConditionContexts()
-   * @see \Drupal\block\Event\BlockContextEvent
+   * @see \Drupal\block\Event\BlockConditionContextEvent
    */
-  const BLOCK_CONTEXT = 'block.block_context';
+  const CONDITION_CONTEXT = 'block.condition_context';
 
 }
diff --git a/core/modules/block/src/EventSubscriber/BlockContextSubscriberBase.php b/core/modules/block/src/EventSubscriber/BlockContextSubscriberBase.php
index ef69f7d..683e83e 100644
--- a/core/modules/block/src/EventSubscriber/BlockContextSubscriberBase.php
+++ b/core/modules/block/src/EventSubscriber/BlockContextSubscriberBase.php
@@ -7,7 +7,7 @@
 
 namespace Drupal\block\EventSubscriber;
 
-use Drupal\block\Event\BlockContextEvent;
+use Drupal\block\Event\BlockConditionContextEvent;
 use Drupal\block\Event\BlockEvents;
 use Drupal\Component\Plugin\Context\ContextInterface;
 use Symfony\Component\EventDispatcher\EventSubscriberInterface;
@@ -18,23 +18,23 @@
 abstract class BlockContextSubscriberBase implements EventSubscriberInterface {
 
   /**
-   * @var \Drupal\block\BlockPluginInterface
+   * @var \Drupal\Core\Condition\ConditionPluginBag
    */
-  protected $block;
+  protected $conditions;
 
   /**
    * {@inheritdoc}
    */
   public static function getSubscribedEvents() {
-    $events[BlockEvents::BLOCK_CONTEXT][] = 'onBlockContext';
+    $events[BlockEvents::CONDITION_CONTEXT][] = 'onBlockConditionContext';
     return $events;
   }
 
   /**
    * Subscribes to the event and delegates to the subclass.
    */
-  public function onBlockContext(BlockContextEvent $event) {
-    $this->block = $event->getBlock();
+  public function onBlockConditionContext(BlockConditionContextEvent $event) {
+    $this->conditions = $event->getConditions();
     $this->determineBlockContext();
   }
 
@@ -54,7 +54,7 @@ public function onBlockContext(BlockContextEvent $event) {
    * @return $this
    */
   public function addContext($name, ContextInterface $context) {
-    $this->block->addContext($name, $context);
+    $this->conditions->addContext($name, $context);
     return $this;
   }