My guess would be that this EULA was derived from a boilerplate Google EULA with a search/replace done on it. Apparently, it's very similar to the Google Docs EULA.
Other than the limited license set forth in Section 11, Google acknowledges and agrees that it obtains no right, title or interest from you (or your licensors) under these Terms in or to any Content that you submit, post, transmit or display on, or through, the Services, including any intellectual property rights which subsist in that Content (whether those rights happen to be registered or not, and wherever in the world those rights may exist). Unless you have agreed otherwise in writing with Google, you agree that you are responsible for protecting and enforcing those rights and that Google has no obligation to do so on your behalf.
11.1 You retain copyright and any other rights you already hold in Content which you submit, post or display on or through, the Services. By submitting, posting or displaying the content you give Google a perpetual, irrevocable, worldwide, royalty-free, and non-exclusive licence to reproduce, adapt, modify, translate, publish, publicly perform, publicly display and distribute any Content which you submit, post or display on or through, the Services. This licence is for the sole purpose of enabling Google to display, distribute and promote the Services and may be revoked for certain Services as defined in the Additional Terms of those Services.
Google allows you to retain copyright over your content. That's great. So if you send a copy of your manuscript to your publisher using Chrome, you technically will always be "the owner." You can still earn royalties from your content, and enter into contracts with publishers or other parties that want to license your content.
But Google will still have a "perpetual, irrevocable, worldwide, royalty-free, and non-exclusive licence to reproduce, adapt, modify, translate, publish, publicly perform, publicly display and distribute any Content which you submit, post or display on or through" the browser.
Usually, when we own rights to something, it gives us the power to do all those things without being bothered by someone else.
So in layman's terms, this essentially makes them "co-owner" of your content. They can license it to others, collect revenues (albeit not technically "royalties") from its sale, copy it at will, alter it at will. They don't have to have your permission to do any of this.
And that's just the intellectual property side. Forget about privacy with regard to your personal life or with regard to trade secrets.
They actually don't have the rights to license it to others. They're not co-owners, nor do they pretend to be, hence "You retain copyright and any other rights you already hold in Content which you submit, post or display on or through, the Services."
But their license justly protects them from being sued because you uploaded a video to YouTube that became a hit, and then you decide you want to sue them because they're hosting a video you submitted but now want to charge people for.
