The string noted above is easy to fix, but there are two other strings that I don't know how to update:

"Google has flagged [extension name] as malicious and installation has been prevented."

"[extension name] was installed remotely" (Title of the notification that an extension or app was disabled due to it being installed server side, requiring an explicit permission check from the user.)

Where does the second one (flagged as malicious, installation prevented) show up exactly?

I've requested that +konsto@ make the change to the third one (see crbug.com/618140).

+rdevlin to answer #2. I couldn't find an example blacklisted extension to test. From reading the code it looks like it may only show up in the console.

Mac triage: Assigning to rdevlin.cronin@

@2, 3: The malicious extension case occurs when the user tries to install a blacklisted extension.  What do we want this one to read?

My understanding is that it's no longer possible for users to encounter an extension that has been blacklisted at all (therefore no way for a user to attempt to install a blacklisted extension). 

Do we know how often (if at all) that string is being displayed/triggered?

Wouldn't it be possible for non-CWS installs? I think the answer is "seldom enough that we don't care too much about the string".

How about: "Foobar wasn't added because Google has flagged it as malicious."

SGTM

+emilyschechter@ has a proposal right now for our SafeBrowsing download warnings. 

Could we use something structurally similar here? 
("flagged" in particular isn't something I've seen before).

for reference, the current string is

  Google has flagged "Foobar" as malicious and installation has been prevented.

that's where I got "flagged" from.

I'm probably not the right owner for this until we finalize string choices.  Over to srahim@ for that.

I'd recommend "This extension may be unsafe, so it can't be installed." to be consistent with the update we made last year to the string that appears on chrome://extensions when we disable an extension:

https://bugs.chromium.org/p/chromium/issues/detail?id=753636
That string is: "Disabled by Chrome. This extension may be unsafe."

SG, Devlin?