Add in-profile external_extensions.json file for Chrome OS OEM customization.

chrome/common/chrome_paths.cc

Index: chrome/common/chrome_paths.cc
diff --git a/chrome/common/chrome_paths.cc b/chrome/common/chrome_paths.cc
index 51aa0191d067a407eff0621949c2a734589ffb71..957c83fb4320548701b08a5e8440181f887b6288 100644
--- a/chrome/common/chrome_paths.cc
+++ b/chrome/common/chrome_paths.cc
@@ -320,6 +320,14 @@ bool PathProvider(int key, FilePath* result) {
       break;
     }
 #endif
+#if defined(OS_CHROMEOS)
+    case chrome::DIR_USER_EXTERNAL_EXTENSIONS: {
+      if (!PathService::Get(chrome::DIR_USER_DATA, &cur))

[Erik does not do reviews, 2011/01/21 17:05:25]

I haven't been following your conversations with Dmitry here, but this seems a
bit odd.  How will the files get written separately into each user's profile? 
Won't it need to be in some shared location?

[Dmitry Polukhin, 2011/01/21 17:46:19]

It can't be some shared location because it needs to be writable by user. If it
is writable, it is security issue that one user will be able to install
extensions to all other user on this machine. There is solution with shared
location but it requires signing of the file itself so if file was unauthorized
we can detect it and don't apply. Moreover we already have such shared location
/opt/google/chrome/extensions/... Per-user location was chosen as a compromise
solution that is secure and is applied only once (i.e. if some app is installed
initially, it won't be removed with some OS update or server changes).

+        return false;
+      cur = cur.Append(FILE_PATH_LITERAL("External Extensions"));
+      break;
+    }
+#endif
     default:
       return false;
   }