Fix a download regression.
Fix a download regression.

FilePath::Extension() returns ".extension" whereas file_util::GetExtensionFromFilename() returns just "extension"

Review URL: http://codereview.chromium.org/27071

git-svn-id: dd90618784b6a4b323ea0c23a071cb1c9e6f2ac7@10221 4ff67af0-8c30-449e-8e8b-ad334ec8d88c

wistoch/meego-app-browser,wistoch/meego-app-browser,wistoch/meego-app-browser,wistoch/meego-app-browser,wistoch/meego-app-browser,wistoch/meego-app-browser,wistoch/meego-app-browser,wistoch/meego-app-browser,wistoch/meego-app-browser,wistoch/meego-app-browser