Warn users about potentially unwanted downloads.

chrome/common/extensions/api/downloads.idl

Index: chrome/common/extensions/api/downloads.idl
diff --git a/chrome/common/extensions/api/downloads.idl b/chrome/common/extensions/api/downloads.idl
index af6eac15c19f965681d6178197bef9d32e4b54a8..877d65542e1db61414691eefb286e6564b292435 100644
--- a/chrome/common/extensions/api/downloads.idl
+++ b/chrome/common/extensions/api/downloads.idl
@@ -76,12 +76,14 @@ namespace downloads {
   //     <dt>host</dt>
   //     <dd>The download came from a host known to distribute malicious
   //     binaries and is likely dangerous.</dd>
+  //     <dt>unwanted</dt>

[benjhayden, 2013/07/22 20:16:19]

"unwanted" is very vague.
How about "modifiesSettings"?

[asanka, 2013/07/23 15:10:36]

This is intentionally vague. Chrome gets this signal from the SafeBrowsing
service. The service currently generates this signal based on whether a binary
changes browser or system settings. This is likely to change in the future.

In general, I'm not sure whether the danger type constants should be part of the
(imminently stabilizing) extensions API. The danger types have changed in the
past and will probably change in number and meaning in the future. I don't think
each such change should require a change to a stable extensions API.

I can change this to potentiallyUnwanted so that it's clear that this is a fuzzy
signal. Or we could fold this into 'file'. I'll upload a new patchset once we
figure out what to do here.

+  //     <dd>The download could make changes to browser or system settings.</dd>
   //     <dt>safe</dt>
   //     <dd>The download presents no known danger to the user's computer.</dd>
   //     <dt>accepted</dt>
   //     <dd>The user has accepted the dangerous download.</dd>
   // </dl>
-  enum DangerType {file, url, content, uncommon, host, safe, accepted};
+  enum DangerType {file, url, content, uncommon, host, unwanted, safe, accepted};
 
   // <dl><dt>in_progress</dt>
   //     <dd>The download is currently receiving data from the server.</dd>