Fix a crash in ChromeActiveDocument::IOleObject_SetClientSite. Check validity of existing document soite before QI for doc host handler.
Fix a crash in ChromeActiveDocument::IOleObject_SetClientSite.
Check validity of existing document soite before QI for
doc host handler.

BUG=37008
TEST=none
TBR=ananta

Review URL: http://codereview.chromium.org/660255

git-svn-id: dd90618784b6a4b323ea0c23a071cb1c9e6f2ac7@40235 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