GetSignatureResultHistogram 601 chrome/browser/extensions/install_verifier.cc GetSignatureResultHistogram(CALLBACK_NO_SIGNATURE); GetSignatureResultHistogram 603 chrome/browser/extensions/install_verifier.cc GetSignatureResultHistogram(CALLBACK_INVALID_SIGNATURE); GetSignatureResultHistogram 605 chrome/browser/extensions/install_verifier.cc GetSignatureResultHistogram(CALLBACK_VALID_SIGNATURE);