Andy Rubin’s departure from his post as Google’s (GOOG) Android boss on Wednesday was surprising because Android under his watch has steadily risen to become the world’s most popular mobile operating system. A new report in the Wall Street Journal, however, hints that Rubin’s departure was more about speeding up the integration of Android and Google’s Chrome operating system than anything else.

Unnamed sources have told the Journal that Rubin was often too independent from other Google divisions and “sometimes clashed with others regarding the Google services that would appear on Android.” The Journal’s sources also say that “the Android and Chrome units had a difficult time working together to bring the Chrome Web browser to Android devices in 2012, replacing the Web browser that the Android team had built.”

Rubin’s replacement, Sundar Pichai, currently heads Google’s Chrome division and is described by the Journal’s sources as “more easy-going.” For this reason, the Journal hints that Pichai could be the better choice “to balance the increasing overlap between Android and Chrome” going forward.

Prior to joining BGR as News Editor, Brad Reed spent five years covering the wireless industry for Network World. His first smartphone was a BlackBerry but he has since become a loyal Android user.