Merge 100224 - Make Chrome Frame registration and unregistration more robust and make it return e...

Merge 100224 - Make Chrome Frame registration and unregistration more robust and make it return extra information in the failure code.



Specifically, there are a series of registration changes made by Chrome Frame at registration and unregistration time. Previously, if any of those changes failed, the previous changes were left and subsequent changes were not made.



During registration this could result in partial registration data being left if one of the items failed which is bad but wasn't a problem in practice, because if ever registration failed, unregistration would then be performed by the installer. Also the most likely step to fail happens first.



During unregistration, if any of the steps fail, the remaining unregistration steps will not be taken. This is bad, as uninstallation is a best effort, "clean up everything you can" type thing.



Changed this to for registration roll back the previous N-1 steps of step N fails and for unregistration to attempt to perform all N steps disregarding failures.



Updated installer logging.



BUG=94848
TEST=Unregistration of e.g. the user-agent modification should always be performed even if an earlier step fails.

Review URL: http://codereview.chromium.org/7824010



TBR=robertshield@chromium.org
Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=102982