diff --git a/core/includes/common.inc b/core/includes/common.inc
index 3215de9..825ffba 100644
--- a/core/includes/common.inc
+++ b/core/includes/common.inc
@@ -1151,17 +1151,12 @@ function format_plural($count, $singular, $plural, array $args = array(), array
  *
  * @return
  *   An integer representation of the size in bytes.
+ *
+ * @deprecated as of Drupal 8.0. Use
+ *   \Drupal\Core\Bootstrap\Bootstrap::parseSize() directly instead.
  */
 function parse_size($size) {
-  $unit = preg_replace('/[^bkmgtpezy]/i', '', $size); // Remove the non-unit characters from the size.
-  $size = preg_replace('/[^0-9\.]/', '', $size); // Remove the non-numeric characters from the size.
-  if ($unit) {
-    // Find the position of the unit in the ordered string which is the power of magnitude to multiply a kilobyte by.
-    return round($size * pow(DRUPAL_KILOBYTE, stripos('bkmgtpezy', $unit[0])));
-  }
-  else {
-    return round($size);
-  }
+  return Bootstrap::parseSize($size);
 }
 
 /**
diff --git a/core/lib/Drupal/Core/Bootstrap/Bootstrap.php b/core/lib/Drupal/Core/Bootstrap/Bootstrap.php
index 3225eed..f29ed75 100644
--- a/core/lib/Drupal/Core/Bootstrap/Bootstrap.php
+++ b/core/lib/Drupal/Core/Bootstrap/Bootstrap.php
@@ -10,6 +10,14 @@
  * Provides helper methods for bootstrapping Drupal.
  */
 class Bootstrap {
+
+  /**
+   * The number of bytes in a kilobyte.
+   *
+   * For more information, visit http://en.wikipedia.org/wiki/Kilobyte.
+   */
+  const DRUPAL_KILOBYTE = 1024;
+
   /**
    * Compares the memory required for an operation to the available memory.
    *
@@ -37,7 +45,7 @@ function checkMemoryLimit($required, $memory_limit = NULL) {
     // - The memory limit is set to unlimited (-1).
     // - The memory limit is greater than or equal to the memory required for
     //   the operation.
-    return ((!$memory_limit) || ($memory_limit == -1) || (parse_size($memory_limit) >= parse_size($required)));
+    return ((!$memory_limit) || ($memory_limit == -1) || (self::parseSize($memory_limit) >= self::parseSize($required)));
   }
 
   /**
@@ -102,4 +110,27 @@ function overrideServerVariables($variables = array()) {
     // Replace elements of the $_SERVER array, as appropriate.
     $_SERVER = $variables + $_SERVER + $defaults;
   }
+
+  /**
+   * Parses a given byte count.
+   *
+   * @param $size
+   *   A size expressed as a number of bytes with optional SI or IEC binary unit
+   *   prefix (e.g. 2, 3K, 5MB, 10G, 6GiB, 8 bytes, 9mbytes).
+   *
+   * @return
+   *   An integer representation of the size in bytes.
+   */
+  function parseSize($size) {
+    $unit = preg_replace('/[^bkmgtpezy]/i', '', $size); // Remove the non-unit characters from the size.
+    $size = preg_replace('/[^0-9\.]/', '', $size); // Remove the non-numeric characters from the size.
+    if ($unit) {
+      // Find the position of the unit in the ordered string which is the power of magnitude to multiply a kilobyte by.
+      return round($size * pow(self::DRUPAL_KILOBYTE, stripos('bkmgtpezy', $unit[0])));
+    }
+    else {
+      return round($size);
+    }
+  }
+
 }
diff --git a/core/tests/Drupal/Tests/Core/Bootstrap/MiscUnitTest.php b/core/tests/Drupal/Tests/Core/Bootstrap/MiscUnitTest.php
index 7c91054..3518cd2 100644
--- a/core/tests/Drupal/Tests/Core/Bootstrap/MiscUnitTest.php
+++ b/core/tests/Drupal/Tests/Core/Bootstrap/MiscUnitTest.php
@@ -23,12 +23,6 @@ public static function getInfo() {
     );
   }
 
-  function setUp() {
-    // @todo think about removing this and converting to components.
-    // Some procedural functions called from within require common.inc.
-    require_once __DIR__ . '/../../../../../includes/common.inc';
-  }
-
   /**
    * Tests that the Bootstrap::checkMemoryLimit() method works as expected.
    */
@@ -41,13 +35,13 @@ function testCheckMemoryLimit() {
     // high.
     $twice_avail_memory = ($memory_limit * 2) . 'MB';
     // The function should always return true if the memory limit is set to -1.
-    $this->assertTrue(drupal_check_memory_limit($twice_avail_memory, -1), 'drupal_check_memory_limit() returns TRUE when a limit of -1 (none) is supplied');
+    $this->assertTrue(Bootstrap::checkMemoryLimit($twice_avail_memory, -1), 'Bootstrap::checkMemoryLimit() returns TRUE when a limit of -1 (none) is supplied');
 
     // Test that even though we have 30MB of memory available - the function
     // returns FALSE when given an upper limit for how much memory can be used.
-    $this->assertFalse(drupal_check_memory_limit('30MB', '16MB'), 'drupal_check_memory_limit() returns FALSE with a 16MB upper limit on a 30MB requirement.');
+    $this->assertFalse(Bootstrap::checkMemoryLimit('30MB', '16MB'), 'Bootstrap::checkMemoryLimit() returns FALSE with a 16MB upper limit on a 30MB requirement.');
 
     // Test that an equal amount of memory to the amount requested returns TRUE.
-    $this->assertTrue(drupal_check_memory_limit('30MB', '30MB'), 'drupal_check_memory_limit() returns TRUE when requesting 30MB on a 30MB requirement.');
+    $this->assertTrue(Bootstrap::checkMemoryLimit('30MB', '30MB'), 'Bootstrap::checkMemoryLimit() returns TRUE when requesting 30MB on a 30MB requirement.');
   }
 }