Add comments and update bug numbers for some layout 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
 //
@@ skipping 2915 matching lines @@
 // WebKit merge 50756:50820, possibly due to WebKit r50808/r50786 and Chromium r31715
 BUG27553 WIN MAC : LayoutTests/fast/text/atsui-partial-selection.html = IMAGE
 
 // WebKit merge 50840:50929
 BUG27555 : LayoutTests/accessibility/document-attributes.html = TEXT
 BUG27555 MAC : LayoutTests/fast/forms/input-file-re-render.html = FAIL
 
 BUG27555 : LayoutTests/media/media-fullscreen-inline.html = TIMEOUT
 BUG27555 : LayoutTests/media/media-fullscreen-not-in-document.html = TIMEOUT
 
-BUG27555 WIN LINUX : LayoutTests/fast/canvas/canvas-shadow.html = TEXT
+BUG22700 WIN LINUX : LayoutTests/fast/canvas/canvas-shadow.html = TEXT
 
 // hbono's new test.
 BUG27679 WIN LINUX MAC : LayoutTests/fast/events/ime-composition-events-001.html = TEXT
 
 // Failures from merge 50972:51042
+// The test requires DRT/Test Shell to support error page handling.
 BUG27850 : LayoutTests/fast/history/back-forward-reset-after-error-handling.html = TEXT
+// Need to update chromium so the web frame delegate is informed when window objects
+// in isolated worlds are cleared.
 BUG27849 : LayoutTests/http/tests/security/isolatedWorld/didClearWindowObject.html = TEXT
 
 // Failures from merge 51042:51062
 BUG27923: LayoutTests/accessibility/aria-labelledby-overrides-label.html = TEXT
 
 // Failures from merge 51062:51075
 BUG27996 : LayoutTests/fast/inspector-support/uncaught-dom1-exception.html = TEXT
 BUG27996 : LayoutTests/fast/inspector-support/uncaught-dom3-exception.html = TEXT
 BUG27996 : LayoutTests/fast/inspector-support/uncaught-dom8-exception.html = TEXT
 BUG28034 MAC : LayoutTests/http/tests/security/XFrameOptions/x-frame-options-deny.html = PASS FAIL
@@ skipping 25 matching lines @@
 // Started failing with move from Lighttpd to Apache on Mac.
 // Since we have some bots on Lighttpd and some on Apache, mark it as flaky for
 // now. Once we decide on one or the other, then we can address these tests.
 BUG_OJAN MAC : LayoutTests/http/tests/loading/text-content-type-with-binary-extension.html = TEXT PASS
 BUG_OJAN MAC : LayoutTests/http/tests/xmlhttprequest/web-apps/012.html = TEXT PASS
 
 // Failures in TestShell that resulted from Mac plugin/focus fixes in r32631.
 BUG28380 MAC : LayoutTests/fast/events/tabindex-focus-blur-all.html = CRASH FAIL
 
 // New tests. Failures from merge 51253:51310.
-BUG28605 : LayoutTests/plugins/reloadplugins-no-pages.html = TEXT
-BUG28605 : LayoutTests/plugins/reloadplugins-and-pages.html = TIMEOUT
+// Needs to implement NPN_reloadPlugins and add reloadPluginNoPages & reloadPluginAndPages
+// to plugin object.
+BUG29018 : LayoutTests/plugins/reloadplugins-no-pages.html = TEXT
+BUG29018 : LayoutTests/plugins/reloadplugins-and-pages.html = TIMEOUT
 BUG28605 WIN LINUX : LayoutTests/svg/filters/big-sized-filter.svg = IMAGE
 BUG28605 : LayoutTests/svg/filters/big-sized-filter-2.svg = MISSING
 BUG28605 WIN LINUX : LayoutTests/svg/filters/filterRes.svg = IMAGE
 
 // New tests. Failures from merge 51210:51325.
 BUG28646 : LayoutTests/editing/selection/transformed-selection-rects.html = FAIL
 
 // New failures from merge 51406:51410.
 BUG28905 : LayoutTests/http/tests/security/isolatedWorld/world-reuse.html = FAIL
 BUG28905 WONTFIX SKIP : LayoutTests/plugins/qt-qwidget-plugin.html = FAIL
 
 // New failures from merge 51412:51455.
 BUG28916 MAC : LayoutTests/editing/pasteboard/paste-xml.xhtml = IMAGE+TEXT
 BUG_HAMAJI WIN LINUX : LayoutTests/editing/selection/last-empty-inline.html = TEXT
 
 // Flaky test from r51224:r51237 roll.
 BUG28918 DEBUG : LayoutTests/storage/domstorage/localstorage/iframe-events.html = CRASH PASS
 
 // Flaky test added by r51350.
 BUG28918 : LayoutTests/http/tests/cache/subresource-failover-to-network.html = PASS TEXT