Add option to install an ephemeral app to ChromeOS shelf context menu

chrome/app/generated_resources.grd

 <?xml version="1.0" encoding="utf-8"?>
 
 <!--
 This file contains definitions of resources that will be translated for each
 locale.  The variables is_win, is_macosx, is_linux, and is_posix are available
 for making strings OS specific.  Other platform defines such as use_titlecase
 are declared in build/common.gypi.
 -->
 
 <grit base_dir="." latest_public_release="0" current_release="1"
@@ skipping 5180 matching lines @@
         </message>
         <message name="IDS_SETTINGS_APP_PROFILES_SWITCH_BUTTON_LABEL" desc="The label that appears on the profile switch user button in the Settings App to allow a user to switch the app launcher profile to the current selection.">
           Switch user
         </message>
         <message name="IDS_SETTINGS_APP_SYNC_OVERVIEW" desc="The message that appears in the non-browser Settings App when sync has not been set up by the user.">
           Sign in with your Google Account to allow apps to synchronize settings and provide other customized services.
         </message>
       </if>
 
       <!-- Packaged Apps -->
-      <if expr="is_win">
-        <message name="IDS_APP_INSTALL_TITLE" desc="Caption for installing an ephemeral app">
-          Install app
-        </message>
-      </if>
+      <message name="IDS_APP_INSTALL_TITLE" desc="Caption for installing an ephemeral app">
+        Install app
+      </message>
 
       <!-- Components -->
       <message name="IDS_COMPONENTS_TITLE" desc="Title for the chrome://components page.">
         Components
       </message>
       <message name="IDS_COMPONENTS_VERSION" desc="The label in front of a component version number.">
         Version:
       </message>
       <message name="IDS_COMPONENTS_NONE_INSTALLED" desc="Text that lets the user know that no components are installed.">
         No components installed.
@@ skipping 8946 matching lines @@
     <message name="IDS_FLAGS_EXTENSION_CONTENT_VERIFICATION_ENFORCE" desc="Description of the 'Extension Content Verification' enforce mode">
       Enforce (try to get hashes, and enforce them if successful)
     </message>
 
     <message name="IDS_FLAGS_EXTENSION_CONTENT_VERIFICATION_ENFORCE_STRICT" desc="Description of the 'Extension Content Verification' enforce strict mode">
       Enforce strict (hard fail if we can't get hashes)
     </message>
   </messages>
   </release>
 </grit>