Fixed WebDragData's wrong dependency.

Source/core/core.gypi

 {
     'includes': [
         'core_generated.gypi',
     ],
     'variables': {
         # Files for which bindings (.cpp and .h files) will be generated
         'core_idl_files': [
             'animation/Animation.idl',
             'animation/AnimationEffect.idl',
             'animation/AnimationNode.idl',
@@ skipping 986 matching lines @@
             'clipboard/DataObject.cpp',
             'clipboard/DataObject.h',
             'clipboard/DataObjectItem.cpp',
             'clipboard/DataObjectItem.h',
             'clipboard/DataTransfer.cpp',
             'clipboard/DataTransfer.h',
             'clipboard/DataTransferItem.cpp',
             'clipboard/DataTransferItem.h',
             'clipboard/DataTransferItemList.cpp',
             'clipboard/DataTransferItemList.h',
+            'clipboard/DraggedIsolatedFileSystem.cpp',
+            'clipboard/DraggedIsolatedFileSystem.h',
             'clipboard/Pasteboard.cpp',
             'clipboard/Pasteboard.h',
             'css/BasicShapeFunctions.cpp',
             'css/BinaryDataFontFaceSource.cpp',
             'css/BinaryDataFontFaceSource.h',
             'css/CSSBasicShapes.cpp',
             'css/CSSBorderImage.cpp',
             'css/CSSBorderImage.h',
             'css/CSSBorderImageSliceValue.cpp',
             'css/CSSBorderImageSliceValue.h',
@@ skipping 2791 matching lines @@
             'rendering/RenderingTestHelper.h',
             'streams/ExclusiveStreamReaderTest.cpp',
             'streams/ReadableStreamTest.cpp',
             'testing/PrivateScriptTestTest.cpp',
             'testing/UnitTestHelpers.cpp',
             'testing/UnitTestHelpers.h',
             'xml/parser/SharedBufferReaderTest.cpp',
         ],
     }
 }