MAGETWO-29705: Fixed confusing Filesystem Read/Write Interfaces

Author: Joan He

dev/tests/unit/testsuite/Magento/Framework/Less/File/Collector/LibraryTest.php

@@ -72,8 +72,8 @@ public function setup()
             ->will(
                 $this->returnValueMap(
                     [
-                        [DirectoryList::LIB_WEB, $this->libraryDirectoryMock],
-                        [DirectoryList::THEMES, $this->themesDirectoryMock],
+                        [DirectoryList::LIB_WEB, Filesystem\DriverPool::FILE, $this->libraryDirectoryMock],
+                        [DirectoryList::THEMES, Filesystem\DriverPool::FILE, $this->themesDirectoryMock],
                     ]
                 )
             );

dev/tests/unit/testsuite/Magento/Framework/View/Asset/MinifiedTest.php

@@ -6,6 +6,7 @@
 namespace Magento\Framework\View\Asset;
 
 use Magento\Framework\App\Filesystem\DirectoryList;
+use Magento\Framework\Filesystem\DriverPool;
 
 class MinifiedTest extends \PHPUnit_Framework_TestCase
 {
@@ -62,8 +63,8 @@ protected function setUp()
         $this->_filesystem->expects($this->any())
             ->method('getDirectoryRead')
             ->will($this->returnValueMap([
-                [DirectoryList::STATIC_VIEW, $this->_staticViewDir],
-                [DirectoryList::ROOT, $this->_rootDir],
+                [DirectoryList::STATIC_VIEW, DriverPool::FILE, $this->_staticViewDir],
+                [DirectoryList::ROOT, DriverPool::FILE, $this->_rootDir],
             ]));
         $this->_filesystem->expects($this->any())
             ->method('getDirectoryWrite')

dev/tests/unit/testsuite/Magento/Framework/View/Asset/SourceTest.php

@@ -7,6 +7,7 @@
 namespace Magento\Framework\View\Asset;
 
 use Magento\Framework\App\Filesystem\DirectoryList;
+use Magento\Framework\Filesystem\DriverPool;
 
 /**
  * @SuppressWarnings(PHPMD.CouplingBetweenObjects)
@@ -245,9 +246,9 @@ protected function initFilesystem()
         $this->varDir = $this->getMockForAbstractClass('Magento\Framework\Filesystem\Directory\WriteInterface');
 
         $readDirMap = [
-            [DirectoryList::ROOT, $this->rootDirRead],
-            [DirectoryList::STATIC_VIEW, $this->staticDirRead],
-            [DirectoryList::VAR_DIR, $this->varDir],
+            [DirectoryList::ROOT, DriverPool::FILE, $this->rootDirRead],
+            [DirectoryList::STATIC_VIEW, DriverPool::FILE, $this->staticDirRead],
+            [DirectoryList::VAR_DIR, DriverPool::FILE, $this->varDir],
         ];
 
         $this->filesystem->expects($this->any())

dev/tests/unit/testsuite/Magento/Framework/View/Element/TemplateTest.php

@@ -5,6 +5,8 @@
  */
 namespace Magento\Framework\View\Element;
 
+use Magento\Framework\Filesystem\DriverPool;
+
 class TemplateTest extends \PHPUnit_Framework_TestCase
 {
     /**
@@ -50,9 +52,9 @@ protected function setUp()
         $this->_filesystem->expects($this->any())
             ->method('getDirectoryRead')
             ->will($this->returnValueMap([
-                [\Magento\Framework\App\Filesystem\DirectoryList::THEMES, $themesDirMock],
-                [\Magento\Framework\App\Filesystem\DirectoryList::APP, $appDirMock],
-                [\Magento\Framework\App\Filesystem\DirectoryList::ROOT, $this->rootDirMock],
+                [\Magento\Framework\App\Filesystem\DirectoryList::THEMES, DriverPool::FILE, $themesDirMock],
+                [\Magento\Framework\App\Filesystem\DirectoryList::APP, DriverPool::FILE, $appDirMock],
+                [\Magento\Framework\App\Filesystem\DirectoryList::ROOT, DriverPool::FILE, $this->rootDirMock],
             ]));
 
         $this->_templateEngine = $this->getMock(