linux: search Chrome-specific plugin directories before Mozilla
linux: search Chrome-specific plugin directories before Mozilla

As discussed in
http://groups.google.com/group/chromium-dev/browse_thread/thread/7a70e5fcbac786a9

Review URL: http://codereview.chromium.org/195044

git-svn-id: dd90618784b6a4b323ea0c23a071cb1c9e6f2ac7@25783 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