Add concept of slow tests.

webkit/tools/layout_tests/test_expectations.txt

 // This file consists of lines with specifications of what
 // to expect from layout test cases. The test cases can be directories
 // in which case the expectations apply to all test cases in that
 // directory and any subdirectory. The format of the file is along the
 // lines of:
 //
 // LayoutTests/fast/js/fixme.js = FAIL
 // LayoutTests/fast/js/flaky.js = FAIL PASS
 // LayoutTests/fast/js/crash.js = CRASH TIMEOUT FAIL PASS
 //
 // To add other options:
 // SKIP : LayoutTests/fast/js/no-good.js = TIMEOUT PASS
 // DEBUG : LayoutTests/fast/js/no-good.js = TIMEOUT PASS
 // DEBUG SKIP : LayoutTests/fast/js/no-good.js = TIMEOUT PASS
 // LINUX DEBUG SKIP : LayoutTests/fast/js/no-good.js = TIMEOUT PASS
 // DEFER LINUX WIN : LayoutTests/fast/js/no-good.js = TIMEOUT PASS
 // BUG1234 DEBUG MAC : LayoutTests/fast/js/no-good.js = TIMEOUT PASS
 //
 // BUG[0-9]+: See this bug for more information. Every test that isn't marked
 //            WONTFIX should have a BUG annotation.
 // SKIP: Doesn't run the test.
+// SLOW: The test takes a long time to run, but does not timeout indefinitely.
 // WONTFIX: For tests that we never intend to pass on a given platform.
 // DEFER: Test does not count in our statistics for the current release.
 // DEBUG: Expectations apply only to the debug build.
 // RELEASE: Expectations apply only to release build.
 // LINUX/WIN/MAC: Expectations apply only to these platforms.
 //
 // The format of a test line is as follows:
 // METADATA : relative/path/to/test.html = EXPECTATIONS
 //
 // For example,
 // LINUX : LayoutTests/media = PASS FAIL
 //
 // The above means that all the media tests are flaky, but only on Linux.
 //
 // Notes:
+// -A test cannot be both SLOW and TIMEOUT
 // -A test cannot be both DEFER and WONTFIX
 // -A test can be included twice, but not via the same path.
 // -If a test is included twice, then the more precise path wins.
 // -CRASH tests cannot be DEFER or WONTFIX
 
 // -----------------------------------------------------------------
 // SKIPPED TESTS
 // -----------------------------------------------------------------
 
 // The action taken when trying to load the resource
@@ skipping 988 matching lines @@
 // for the current release.
 BUG10322 DEFER : LayoutTests/accessibility = FAIL
 // Border radius not anti-aliased.
 // New test. We should fix it, but it doesn't need to block the current release
 BUG10322 DEFER WIN : LayoutTests/fast/borders/fieldsetBorderRadius.html = FAIL
 // Linux pixeltest failure: radial gradients don't have offset focal point
 BUG10322 DEFER WIN LINUX : LayoutTests/fast/gradients/generated-gradients.html = FAIL
 // Linux pixeltest failure: radial gradients don't have offset focal point
 // New test. We should fix it, but it doesn't need to block the current release
 BUG10322 DEFER WIN LINUX : LayoutTests/fast/gradients/simple-gradients.html = FAIL
-// This test isn't hanging, it just takes 12-13 seconds to run, which is more
-// than test_shell allows. However, we shouldn't look into the speed of the test
-// until we have reached PASS status.
-BUG10322 : LayoutTests/http/tests/misc/acid3.html = TIMEOUT FAIL
+// This test isn't hanging, it just takes 12-13 seconds to run.
+BUG10322 SLOW : LayoutTests/http/tests/misc/acid3.html = FAIL
 
 // Expectations for this test changed upstream. We should fix this test, but
 // it doesn't need to block the current release
 BUG10323 DEFER : LayoutTests/http/tests/xmlhttprequest/xmlhttprequest-no-content-length-onProgress.html = FAIL
 
 // Times out because this uses dom storage which we don't implement.
 BUG4360 DEFER SKIP : LayoutTests/security/autocomplete-cleared-on-back.html = TIMEOUT
 
 // Post-MERGE failures: these will all need to be fixed one day
 
@@ skipping 188 matching lines @@
 BUG10353 DEFER : LayoutTests/fast/forms/textarea-rows-cols.html = FAIL
 // Linux pixeltest failure: We, with Windows, are failing to repaint correctly
 BUG10353 WIN LINUX : LayoutTests/fast/repaint/overflow-outline-repaint.html = FAIL
 BUG10353 WIN : LayoutTests/fast/repaint/overflow-scroll-delete.html = FAIL
 // Likely just needs to be baselined.
 BUG10353 MAC LINUX : LayoutTests/fast/forms/form-element-geometry.html = FAIL
 BUG10353 MAC LINUX : LayoutTests/fast/replaced/width100percent-textarea.html = FAIL
 BUG10353 LINUX : LayoutTests/fast/text/drawBidiText.html = FAIL
 BUG10353 LINUX : LayoutTests/http/tests/security/dataURL/xss-DENIED-from-data-url-in-foreign-domain-subframe.html = TIMEOUT PASS
 chrome/fast/dom/xss-DENIED-javascript-variations.html = FAIL
-// This test can end up taking longer than the amount of time we give
-// each test. DEFERd until we find a better way to deal with it.
-BUG10353 DEFER WIN LINUX : LayoutTests/http/tests/misc/dns-prefetch-control.html = TIMEOUT PASS
+
+BUG_OJAN WIN LINUX SLOW : LayoutTests/http/tests/misc/dns-prefetch-control.html = PASS
+
 // This is failing on the mac debug only, not sure why, but it's pretty repeatable on the bots, so we
 // go to the complexity to split out that one case to track any other changes for the other platforms.
 BUG10353 DEBUG MAC : LayoutTests/http/tests/misc/dns-prefetch-control.html = TIMEOUT FAIL PASS
 
 // NEW FOR MERGE 37604:38097
 // This is a Safari specific test used to document the set of global
 // constructors they expose and the exact way they are printed.  Not
 // important - we might even want to ignore it.
 // New tests. We should fix these, but they doesn't need to block the current
 // release
@@ skipping 1186 matching lines @@
 // due to http://trac.webkit.org/changeset/42428.
 BUG10489 LINUX MAC : chrome/fast/dom/messageport-gc.html = TIMEOUT
 
 // New test added by http://trac.webkit.org/changeset/42501.
 // Has already been rebaselined for chromium-win.
 BUG10529 LINUX : LayoutTests/editing/inserting/6703873.html = FAIL
 
 // This test was changed upstream in http://trac.webkit.org/changeset/42447
 // to include window.showModalDialog, which we give as undefined.
 BUG10530 : LayoutTests/fast/dom/Window/window-function-frame-getter-precedence.html = FAIL