By Steve Johnson
sjohnson@mercurynews.com
Posted: 09/15/2009 02:06:54 PM PDT
Updated: 09/16/2009 04:54:15 AM PDT
While disclosing a significant drop in quarterly earnings, San Jose-based Adobe Systems on Tuesday also announced a $1.8 billion deal to buy Omniture, a Utah company whose software is used by businesses to track how their Web-site information is being viewed.
Under the purchase, whi…