Prevent double loading of the Chrome Frame BHO when using the user-level injection technique.
Prevent double loading of the Chrome Frame BHO when using the user-level injection technique.

BUG=53127
TEST=With two chrome_frame_helper.exe processes running, only a single BHO instance is created and SetSite is only called on the BHO once.

Review URL: http://codereview.chromium.org/3338011

git-svn-id: dd90618784b6a4b323ea0c23a071cb1c9e6f2ac7@58723 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