Need to add optional contentType parameter to Blob.slice per latest File API spec (http://dev.w3.org/2006/webapi/FileAPI/#dfn-Blob).
Created attachment 58839 [details] Proposed Patch
(The patch looks good to me though I'm not a reviewer.) > diff --git a/LayoutTests/http/tests/local/resources/send-sliced-dragged-file.js b/LayoutTests/http/tests/local/resources/send-sliced-dragged-file.js > + subfile = (contentType != undefined) ? file.slice(start, length, contentType) : file.slice(start, length); > diff --git a/WebCore/html/Blob.idl b/WebCore/html/Blob.idl > + Blob slice(in long long start, in long long length, in [Optional] DOMString contentType); One question - don't we want to make the contentType parameter [Optional, ConvertUndefinedOrNullToNullString]? Passing undefined value for an optional parameter leaves Blob.type undefined - it sounds a bit awkward to me.
Comment on attachment 58839 [details] Proposed Patch WebCore/html/Blob.h:69 + PassRefPtr<Blob> slice(long long start, long long length, const String& contentType = "") const; Do you really want to pass "" here and not String()?
Created attachment 58933 [details] Proposed Patch All fixed.
Committed as http://trac.webkit.org/changeset/61343.