http/tests/navigation/forward-and-cancel.html has been failing intermittently on Windows and Linux debug bots. See http://test-results.appspot.com/dashboards/flakiness_dashboard.html#showExpectations=true&master=ChromiumWebkit&tests=http%2Ftests%2Fnavigation%2Fforward-and-cancel.html
Also crash on Mac. ASSERTION FAILED: item /b/build/slave/webkit-mac-pinned-dbg/build/src/third_party/WebKit/Source/WebCore/WebCore.gyp/../page/Page.cpp(332) : void WebCore::Page::goBackOrForward(int) [31548:2307:3761365315353461:ERROR:process_util_posix.cc(134)] Received signal 11
No longer reproduces.