diff --git a/core/modules/block/lib/Drupal/block/BlockStorageController.php b/core/modules/block/lib/Drupal/block/BlockStorageController.php
index 3997704..02374ff 100644
--- a/core/modules/block/lib/Drupal/block/BlockStorageController.php
+++ b/core/modules/block/lib/Drupal/block/BlockStorageController.php
@@ -16,6 +16,24 @@
 class BlockStorageController extends ConfigStorageController {
 
   /**
+   * Overrides \Drupal\Core\Config\Entity\ConfigStorageController::create().
+   */
+  public function create(array $values) {
+    $entity = parent::create($values);
+
+    if (!$entity->get('module')) {
+      $definition = $entity->getPlugin()->getDefinition();
+      $entity->set('module', $definition['module']);
+    }
+    $configuration = $entity->get('configuration');
+    if (isset($configuration['cache'])) {
+      $entity->set('cache', $configuration['cache']);
+    }
+
+    return $entity;
+  }
+
+  /**
    * Overrides \Drupal\Core\Config\Entity\ConfigStorageController::load().
    */
   public function load(array $ids = NULL) {
@@ -45,6 +63,13 @@ public function loadByProperties(array $values = array()) {
   protected function preSave(EntityInterface $entity) {
     parent::preSave($entity);
 
+    // Ensure that the theme is stored directly on the entity, to simplify
+    // \Drupal\Core\Config\Entity\ConfigStorageController::loadByProperties().
+    if (!$entity->get('theme')) {
+      list($theme) = explode('.', $entity->id());
+      $entity->set('theme', $theme);
+    }
+
     // Cache settings are stored directly on the block, remove them from
     // configuration.
     $configuration = $entity->get('configuration');
diff --git a/core/modules/block/lib/Drupal/block/Plugin/Core/Entity/Block.php b/core/modules/block/lib/Drupal/block/Plugin/Core/Entity/Block.php
index 775ecfa..7f27640 100644
--- a/core/modules/block/lib/Drupal/block/Plugin/Core/Entity/Block.php
+++ b/core/modules/block/lib/Drupal/block/Plugin/Core/Entity/Block.php
@@ -128,44 +128,25 @@ class Block extends ConfigEntityBase {
   protected $plugin;
 
   /**
-   * Overrides \Drupal\Core\Entity\Entity::__construct().
-   */
-  public function __construct(array $values, $entity_type) {
-    parent::__construct($values, $entity_type);
-
-    // @todo Consider moving to Block::getPlugin().
-    try {
-      $this->instance = drupal_container()->get('plugin.manager.block')->createInstance($this->plugin, $this->configuration);
-      $this->configuration += $this->instance->getConfig();
-    }
-    catch (PluginException $e) {
-      // Ignore blocks belonging to disabled modules, but re-throw valid
-      // exceptions when the module is enabled and the plugin is misconfigured.
-      if (module_exists($this->module)) {
-        throw $e;
-      }
-    }
-
-    // @todo Consider moving to \Drupal\block\BlockStorageController::create().
-    if (!$this->module) {
-      $definition = $this->instance->getDefinition();
-      $this->module = $definition['module'];
-    }
-    if (isset($this->configuration['cache'])) {
-      $this->cache = $this->configuration['cache'];
-    }
-    if (!isset($this->theme) && $id = $this->id()) {
-      list($this->theme) = explode('.', $id);
-    }
-  }
-
-  /**
    * Returns the plugin instance.
    *
    * @return \Drupal\block\BlockInterface
    *   The plugin instance for this block.
    */
   public function getPlugin() {
+    if (!$this->instance) {
+      try {
+        $this->instance = drupal_container()->get('plugin.manager.block')->createInstance($this->plugin, $this->configuration);
+        $this->configuration += $this->instance->getConfig();
+      }
+      catch (PluginException $e) {
+        // Ignore blocks belonging to disabled modules, but re-throw valid
+        // exceptions when the module is enabled and the plugin is misconfigured.
+        if (module_exists($this->module)) {
+          throw $e;
+        }
+      }
+    }
     return $this->instance;
   }
 
diff --git a/core/modules/views/lib/Drupal/views/Tests/UI/OverrideDisplaysTest.php b/core/modules/views/lib/Drupal/views/Tests/UI/OverrideDisplaysTest.php
index 27b2a10..5c654a5 100644
--- a/core/modules/views/lib/Drupal/views/Tests/UI/OverrideDisplaysTest.php
+++ b/core/modules/views/lib/Drupal/views/Tests/UI/OverrideDisplaysTest.php
@@ -80,7 +80,7 @@ function testOverrideDisplays() {
   /**
    * Tests that the wizard correctly sets up default and overridden displays.
    */
-  function _testWizardMixedDefaultOverriddenDisplays() {
+  function testWizardMixedDefaultOverriddenDisplays() {
     // Create a basic view with a page, block, and feed. Give the page and feed
     // identical titles, but give the block a different one, so we expect the
     // page and feed to inherit their titles from the default display, but the
@@ -163,7 +163,7 @@ function _testWizardMixedDefaultOverriddenDisplays() {
   /**
    * Tests that the revert to all displays select-option works as expected.
    */
-  function _testRevertAllDisplays() {
+  function testRevertAllDisplays() {
     // Create a basic view with a page, block.
     // Because there is both a title on page and block we expect the title on
     // the block be overriden.
diff --git a/core/profiles/standard/config/plugin.core.block.bartik.content.yml b/core/profiles/standard/config/plugin.core.block.bartik.content.yml
index d48bd7a..1406a59 100644
--- a/core/profiles/standard/config/plugin.core.block.bartik.content.yml
+++ b/core/profiles/standard/config/plugin.core.block.bartik.content.yml
@@ -1,5 +1,6 @@
 id: bartik.content
 plugin: system_main_block
+theme: bartik
 status: '1'
 cache: '-1'
 visibility:
diff --git a/core/profiles/standard/config/plugin.core.block.bartik.footer.yml b/core/profiles/standard/config/plugin.core.block.bartik.footer.yml
index 910dfa3..4d03200 100644
--- a/core/profiles/standard/config/plugin.core.block.bartik.footer.yml
+++ b/core/profiles/standard/config/plugin.core.block.bartik.footer.yml
@@ -1,5 +1,6 @@
 id: bartik.footer
 plugin: 'system_menu_block:menu-footer'
+theme: bartik
 status: '1'
 cache: '-1'
 label: 'Footer menu'
diff --git a/core/profiles/standard/config/plugin.core.block.bartik.help.yml b/core/profiles/standard/config/plugin.core.block.bartik.help.yml
index b40a88f..0f46023 100644
--- a/core/profiles/standard/config/plugin.core.block.bartik.help.yml
+++ b/core/profiles/standard/config/plugin.core.block.bartik.help.yml
@@ -1,5 +1,6 @@
 id: bartik.help
 plugin: system_help_block
+theme: bartik
 status: '1'
 cache: '-1'
 visibility:
diff --git a/core/profiles/standard/config/plugin.core.block.bartik.login.yml b/core/profiles/standard/config/plugin.core.block.bartik.login.yml
index 09526b8..1e780b6 100644
--- a/core/profiles/standard/config/plugin.core.block.bartik.login.yml
+++ b/core/profiles/standard/config/plugin.core.block.bartik.login.yml
@@ -18,4 +18,5 @@ module: user
 region: sidebar_first
 weight: '0'
 plugin: user_login_block
+theme: bartik
 langcode: und
diff --git a/core/profiles/standard/config/plugin.core.block.bartik.powered.yml b/core/profiles/standard/config/plugin.core.block.bartik.powered.yml
index 6fb1f5d..165d5d0 100644
--- a/core/profiles/standard/config/plugin.core.block.bartik.powered.yml
+++ b/core/profiles/standard/config/plugin.core.block.bartik.powered.yml
@@ -1,5 +1,6 @@
 id: bartik.powered
 plugin: system_powered_by_block
+theme: bartik
 status: '1'
 cache: '-1'
 visibility:
diff --git a/core/profiles/standard/config/plugin.core.block.bartik.search.yml b/core/profiles/standard/config/plugin.core.block.bartik.search.yml
index 6d11ee3..d69e7bb 100644
--- a/core/profiles/standard/config/plugin.core.block.bartik.search.yml
+++ b/core/profiles/standard/config/plugin.core.block.bartik.search.yml
@@ -1,5 +1,6 @@
 id: bartik.search
 plugin: search_form_block
+theme: bartik
 status: '1'
 cache: '-1'
 visibility:
diff --git a/core/profiles/standard/config/plugin.core.block.bartik.tools.yml b/core/profiles/standard/config/plugin.core.block.bartik.tools.yml
index 002402e..40df6d9 100644
--- a/core/profiles/standard/config/plugin.core.block.bartik.tools.yml
+++ b/core/profiles/standard/config/plugin.core.block.bartik.tools.yml
@@ -1,5 +1,6 @@
 id: bartik.tools
 plugin: 'system_menu_block:menu-tools'
+theme: bartik
 status: '1'
 cache: '-1'
 visibility:
diff --git a/core/profiles/standard/config/plugin.core.block.seven.content.yml b/core/profiles/standard/config/plugin.core.block.seven.content.yml
index a0a3d71..8a826c1 100644
--- a/core/profiles/standard/config/plugin.core.block.seven.content.yml
+++ b/core/profiles/standard/config/plugin.core.block.seven.content.yml
@@ -1,5 +1,6 @@
 id: seven.content
 plugin: system_main_block
+theme: seven
 status: '1'
 cache: '-1'
 visibility:
diff --git a/core/profiles/standard/config/plugin.core.block.seven.help.yml b/core/profiles/standard/config/plugin.core.block.seven.help.yml
index 9d20b69..5b3ad82 100644
--- a/core/profiles/standard/config/plugin.core.block.seven.help.yml
+++ b/core/profiles/standard/config/plugin.core.block.seven.help.yml
@@ -1,5 +1,6 @@
 id: bartik.content
 plugin: system_help_block
+theme: seven
 status: '1'
 cache: '-1'
 visibility:
diff --git a/core/profiles/standard/config/plugin.core.block.seven.login.yml b/core/profiles/standard/config/plugin.core.block.seven.login.yml
index 4cfd3d4..7f19040 100644
--- a/core/profiles/standard/config/plugin.core.block.seven.login.yml
+++ b/core/profiles/standard/config/plugin.core.block.seven.login.yml
@@ -1,5 +1,6 @@
 id: seven.login
 plugin: user_login_block
+theme: seven
 status: '1'
 cache: '-1'
 visibility:
diff --git a/core/profiles/testing/config/plugin.core.block.stark.admin.yml b/core/profiles/testing/config/plugin.core.block.stark.admin.yml
index 83ea3b1..e7d832d 100644
--- a/core/profiles/testing/config/plugin.core.block.stark.admin.yml
+++ b/core/profiles/testing/config/plugin.core.block.stark.admin.yml
@@ -1,5 +1,6 @@
 id: stark.admin
 plugin: 'system_menu_block:menu-admin'
+theme: stark
 status: '1'
 cache: '-1'
 visibility:
diff --git a/core/profiles/testing/config/plugin.core.block.stark.online.yml b/core/profiles/testing/config/plugin.core.block.stark.online.yml
index 71996b5..db1f2cc 100644
--- a/core/profiles/testing/config/plugin.core.block.stark.online.yml
+++ b/core/profiles/testing/config/plugin.core.block.stark.online.yml
@@ -1,6 +1,7 @@
 id: stark.online
 label: 'Who''s online'
 plugin: user_online_block
+theme: stark
 configuration:
   properties:
     administrative: '1'
diff --git a/core/profiles/testing/config/plugin.core.block.stark.tools.yml b/core/profiles/testing/config/plugin.core.block.stark.tools.yml
index b043215..bda5f0f 100644
--- a/core/profiles/testing/config/plugin.core.block.stark.tools.yml
+++ b/core/profiles/testing/config/plugin.core.block.stark.tools.yml
@@ -1,5 +1,6 @@
 id: stark.tools
 plugin: 'system_menu_block:menu-tools'
+theme: stark
 status: '1'
 cache: '-1'
 visibility: