Internally WebCore should use the more specific CSSMutableStyleDeclaration and CSSComputedStyleDeclaration types. The CSSStyleDeclaration base should be used in the DOM API functions only. This will make it easier to separate internal style sheet implementation from the DOM in the future.
Created attachment 123716 [details]
Attachment 123716 [details] did not pass style-queue:
Failed to run "['Tools/Scripts/check-webkit-style', '--diff-files', u'Source/WebCore/ChangeLog', u'Source/WebCor..." exit_code: 1
Source/WebCore/rendering/RenderLayer.cpp:49: Alphabetical sorting problem. [build/include_order] 
Total errors found: 1 in 14 files
If any of these errors are false positives, please file a bug against check-webkit-style.