Implementing timeout support for XHR

LayoutTests/TestExpectations

 # See http://trac.webkit.org/wiki/TestExpectations for more information on this file.
 
 # -----------------------------------------------------------------
 # SLOW TESTS
 # -----------------------------------------------------------------
 
 crbug.com/24182 [ Debug ] css3/flexbox/multiline-justify-content.html [ Slow ]
 webkit.org/b/91666 [ Mac ] editing/input/emacs-ctrl-o.html [ Failure Slow ]
 webkit.org/b/91666 [ Mac ] editing/pasteboard/emacs-ctrl-k-y-001.html [ Failure Slow ]
 webkit.org/b/91666 [ Mac ] editing/pasteboard/emacs-ctrl-a-k-y.html [ Failure Slow ]
@@ skipping 966 matching lines @@
 # error in the header of the following test.
 crbug.com/24197 fast/css/disabled-author-styles.html
 
 # Test itself passes, but causes subsequent tests to fail.
 webkit.org/b/83260 fast/text/international/embed-bidi-style-in-isolate-crash.html
 
 webkit.org/b/105005 [ Debug ] fast/css/variables/case-insensitive.html [ Pass Crash ]
 
 webkit.org/b/109415 editing/spelling/spellcheck-async.html [ Pass Failure ]
 
-# ResourceRequest needs to support setTimeoutInterval
-webkit.org/b/98397 http/tests/xmlhttprequest/timeout/xmlhttprequest-timeout-aborted.html [ Skip ]
-webkit.org/b/98397 http/tests/xmlhttprequest/timeout/xmlhttprequest-timeout-abortedonmain.html [ Skip ]
-webkit.org/b/98397 http/tests/xmlhttprequest/timeout/xmlhttprequest-timeout-overridesexpires.html [ Skip ]
-webkit.org/b/98397 http/tests/xmlhttprequest/timeout/xmlhttprequest-timeout-simple.html [ Skip ]
-webkit.org/b/98397 http/tests/xmlhttprequest/timeout/xmlhttprequest-timeout-synconmain.html [ Skip ]
-webkit.org/b/98397 http/tests/xmlhttprequest/timeout/xmlhttprequest-timeout-twice.html [ Skip ]
-webkit.org/b/98397 http/tests/xmlhttprequest/timeout/xmlhttprequest-timeout-worker-aborted.html [ Skip ]
-webkit.org/b/98397 http/tests/xmlhttprequest/timeout/xmlhttprequest-timeout-worker-overridesexpires.html [ Skip ]
-webkit.org/b/98397 http/tests/xmlhttprequest/timeout/xmlhttprequest-timeout-worker-simple.html [ Skip ]
-webkit.org/b/98397 http/tests/xmlhttprequest/timeout/xmlhttprequest-timeout-worker-synconworker.html [ Skip ]
-webkit.org/b/98397 http/tests/xmlhttprequest/timeout/xmlhttprequest-timeout-worker-twice.html [ Skip ]
-
 # -----------------------------------------------------------------
 # Inspector tests
 # -----------------------------------------------------------------
 
 # There is no enough plugins support in DRT
 http/tests/inspector/network/network-embed.html [ WontFix ]
 http/tests/inspector/network/network-content-replacement-embed.html [ WontFix ]
 
 # Works slowly, we have an equivalent test that doesn't open Inspector and runs fast.
 [ Linux Debug ] inspector/profiler/cpu-profiler-profiling.html [ WontFix ]
@@ skipping 2750 matching lines @@
 crbug.com/230771 http/tests/security/clipboard/clipboard-file-access.html [ Failure ]
 crbug.com/230771 fast/forms/file/file-input-reset.html [ ImageOnlyFailure ]
 
 # From WebKit's generic expectations.
 # pending functional patch and per-port verification
 webkit.org/b/109954 css3/line-break [ Skip ]
 # pending implementation completion and feature enabling
 webkit.org/b/109570 media/track/regions-webvtt [ Skip ]
 
 crbug.com/231721 [ XP Release ] svg/custom/invisible-text-after-scrolling.xhtml [ Pass Timeout ]