Bug 1372750 - allow generated embedded extensions to work in xpcshell tests r=kmag

MozReview-Commit-ID: AkCnoUTldhI

--HG--
extra : rebase_source : 69e36d7e462ed26740874dbf96a695dd92bdb850

toolkit/components/extensions/ExtensionTestCommon.jsm

@@ -220,6 +220,7 @@ this.ExtensionTestCommon = class ExtensionTestCommon {
                   em:type="2"
                   em:version="${manifest.version}"
                   em:description=""
+                  em:multiprocessCompatible="true"
                   em:hasEmbeddedWebExtension="true"
                   em:bootstrap="true">
 
@@ -230,6 +231,13 @@ this.ExtensionTestCommon = class ExtensionTestCommon {
                           em:minVersion="51.0a1"
                           em:maxVersion="*"/>
                   </em:targetApplication>
+                  <em:targetApplication>
+                    <Description>
+                      <em:id>toolkit@mozilla.org</em:id>
+                      <em:minVersion>0</em:minVersion>
+                      <em:maxVersion>*</em:maxVersion>
+                    </Description>
+                  </em:targetApplication>
               </Description>
           </RDF>
         `,