According to Google, OAuth 1.0 was official deprecated on April 20, 2012 (Google OAuth 1.0 Reference). They suggest migration to OAuth 2.0 as soon as possible.
The attached patch adds full OAuth 2.0 support while still ensuring full compatibility with all aspects of the Google Analytics Reports module.
The new implementation of OAuth2 kills the reports page thus. We rolled up all this functionality in one patch:
#1678306: Add Support for OAuth2 Authentication
#2368151: Build reports in Reports module on Views
#2169159: Migrate from Chart module to Charts