Better fix for Windows test failure.  Delete the old file before trying to copy the plugin files over.
Better fix for Windows test failure.  Delete the old file
before trying to copy the plugin files over.

Review URL: http://codereview.chromium.org/3052041

git-svn-id: dd90618784b6a4b323ea0c23a071cb1c9e6f2ac7@55096 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