I believe we do not use the UNUSED_PARAM macro in Chromium code. At least, grepping for it in all code in WebKit/chromium/src/ yields a single result: GraphicsContext3D.cpp. There is a better way to achieve the same thing: don't give names to parameters. We should clean that up.
UNUSED_PARAM is only needed when ifdeffing out code. You use UNUSED_PARAM in the #else block.
Created attachment 53581 [details]
Attachment 53581 [details] did not pass style-queue:
Failed to run "WebKitTools/Scripts/check-webkit-style" exit_code: 1
WebKit/chromium/ChangeLog:6: Line contains tab character. [whitespace/tab] 
Total errors found: 1 in 2 files
If any of these errors are false positives, please file a bug against check-webkit-style.
Comment on attachment 53581 [details]
Landed as r57771.