Oilpan: A thread that is not attached to Oilpan shouldn't create a CrossThreadPersistent

Source/wtf/wtf.gypi

 # For GN compatibility, this file can not have any conditions.
 {
     'variables': {
         'wtf_files': [
             'ASCIICType.h',
             'AddressSpaceRandomization.cpp',
             'AddressSpaceRandomization.h',
             'Alignment.h',
             'ArrayBuffer.cpp',
             'ArrayBuffer.h',
@@ skipping 107 matching lines @@
             'ThreadingPrimitives.h',
             'ThreadingPthreads.cpp',
             'ThreadingWin.cpp',
             'TreeNode.h',
             'TypeTraits.cpp',
             'TypeTraits.h',
             'TypedArrayBase.h',
             'Uint16Array.h',
             'Uint32Array.h',
             'Uint8Array.h',
+            'UnretainedPtr.h',
             'Vector.h',
             'VectorTraits.h',
             'WTF.cpp',
             'WTF.h',
             'WTFExport.h',
             'WTFThreadData.cpp',
             'WTFThreadData.h',
             'WeakPtr.h',
             'asm/SaturatedArithmeticARM.h',
             'dtoa.cpp',
@@ skipping 95 matching lines @@
             'text/TextCodecUTF8Test.cpp',
             'text/WTFStringTest.cpp',
         ],
         'wtf_unittest_helper_files': [
             'testing/WTFTestHelpers.cpp',
             'testing/WTFTestHelpers.h',
             'testing/WTFUnitTestHelpersExport.h',
         ],
     },
 }