Screenshot by Ben Parr/CNET

Sometime in the next 12 months, Google Chrome will become the world's most popular browser, knocking Microsoft's Internet Explorer off the mountain it has ruled for more than a decade.

This fact should scare the pants off of Facebook.

In July 2008, IE controlled 68.5 percent of the market, according to Statcounter, while Chrome wasn't even on the market. Now Microsoft's browser is down to 34.8 percent market share while Chrome controls 30.9 percent of total browser usage. Chrome has grown by a percentage point the last few months, while IE has dropped by around the same amount.

It's only a matter of time until Google dominates the browser market.

Now you may be asking yourselves: why should Facebook care about the fate of the browser market? Facebook's a social network, not a desktop software company -- why do the browser wars matter?

The answer lies in Google's ambitious plans for Google+, the company's "social spine." It's no secret that Facebook and Google are at war, and that Google would love to take the wind out of Facebook's sails. Nothing less than control of the Web (and billions in ad dollars) is at stake.

Google+ as a standalone product hasn't made a dent in Facebook's growth, though. Google+ may have 170+ million users, but Facebook is still on track for the IPO of the decade.

Google+ wasn't designed as a standalone product, however. It was made to augment and unify all of Google's products. Google wants to become Voltron -- each separate piece (Gmail, Chrome, Android, Google Search, and so on) is strong on its own, but combined it's unstoppable. That's why Google launched Search + Your World, and that's why Google+ integration in Chrome is inevitable.

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Think about that for a moment. In a single update, Google could turn Chrome into its own version of Rockmelt -- it would be a social browser that puts Google+ in front of users before they even have a chance to type Facebook.com in the address bar.

Don't think Google will do it? It's already started releasing extensions that integrate Google+ into Chrome. I suspect that these extensions are just precursors to their eventual integration into Chrome.

Facebook may be king of the Web right now, but the browser is still the gateway users must pass through to access the Web. Facebook can't allow Google to control how 30.9 percent of its users access its Web site, especially as its ally (and investor) Microsoft continues to falter in the browser wars.

Facebook could try to counter Chrome with Facebook integration in IE, but it wouldn't be the game-changing move Facebook needs to put Google on the defensive. The only way Facebook can knock Google off its feet is to build its own browser and use its massive reach to promote it.

The next battle in the war for dominance over the Web is going to be waged at the browser level. The only question is whether Facebook will take up the fight before it's too late.