Check out this bug's details at: http://stackoverflow.com/questions/9393240/about-html5s-new-feature-placeholder-on-firefox
Could you please explain what the WebKit bug is? I only see a link to an external site that discusses Firefox.
We ask to post all relevant details to bugs.webkit.org bugs, because making every engineer click through to external sites and try to extract the information from unrelated discussions is wasteful.
Find sentences below in that page:
"The spec defines the JS property as being on the prototype, not on the object itself. Chrome gets this wrong for all DOM properties; it's a longstanding bug in Chrome."
"This should be a WebKit's bug relevant its implementation to DOM. Safari also has this bug."
*** This bug has been marked as a duplicate of bug 49739 ***