Code: void ExtensionServiceBackend::OnExtensionInstalled(
     const scoped_refptr<const Extension>& extension) {
   CHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
   if (frontend_.get())
    frontend_->OnExtensionInstalled(extension);
 }

Vulnerability Type: 
CWE ID: CWE-20
Summary: Google Chrome before 13.0.782.107 does not ensure that developer-mode NPAPI extension installations are confirmed by a browser dialog, which makes it easier for remote attackers to modify the product's functionality via a Trojan horse extension.
Commit Message: Unrevert: Show the install dialog for the initial load of an unpacked extension
with plugins.

First landing broke some browser tests.

BUG=83273
TEST=in the extensions managmenet page, with developer mode enabled, Load an unpacked extension on an extension with NPAPI plugins. You should get an install dialog.
TBR=mihaip

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@87738 0039d316-1c4b-4281-b951-d872f2087c98