Convert BackForwardList to an abstract base class.
Created attachment 60823 [details]
Attachment 60823 [details] did not build on qt:
Build output: http://webkit-commit-queue.appspot.com/results/3466003
Created attachment 60826 [details]
Updated patch, don't break Qt.
Attachment 60826 [details] did not build on qt:
Build output: http://webkit-commit-queue.appspot.com/results/3436007
Created attachment 60827 [details]
Patch 3 (once more with a feeling)
Hmm, BackForwardList as an interface makes BackForwardListClient unnecessary.
Attachment 60827 [details] did not build on chromium:
Build output: http://webkit-commit-queue.appspot.com/results/3473010
Created attachment 60891 [details]
Attachment 60891 [details] did not pass style-queue:
Failed to run "['WebKitTools/Scripts/check-webkit-style', '--no-squash']" exit_code: 1
WARNING: File exempt from style guide. Skipping: "WebKit/qt/Api/qwebhistory.cpp"
WebCore/history/BackForwardListChromium.cpp:29: Found other header before a header this file implements. Should be: config.h, primary header, blank line, and then alphabetically sorted. [build/include_order] 
Total errors found: 1 in 20 files
If any of these errors are false positives, please file a bug against check-webkit-style.
(In reply to comment #6)
> Hmm, BackForwardList as an interface makes BackForwardListClient unnecessary.
Landed in r62792.
http://trac.webkit.org/changeset/62792 might have broken Chromium Linux Release