Hi, Colin, I found inside //remoting it cannot get the service manager.

From the link: https://chromium.googlesource.com/chromium/src/+/lkgr/docs/old_chromoting_build_instructions.md
I found The HostPowerSaveBlocker runs in a separate process(the GN target "remoting_me2me_host" is an "executable" type). It is built and packaged in a separate application(they call it "host service" in the above *.md). So its process is not child-process of BrowserProcess.

So I guess it is not a part of Chrome, we shouldn't create the service manager connection to it. We can add the "visibility" in //Services/ and allow it to use power-save-blocker directly.

WDYT? Thanks!

Final decision after discussion: 
So far no need to embed the Service Manager in //remoting, especially given that the only concrete use case right now is for Wake Lock. we'll allow //services/device/wake_lock to be visible in GN to //remoting and directly used by it with a comment saying that //remoting is outside of the context of a ServiceManager-based world.