Use PreloadCheckGroup in ExtensionInstallChecker. Make RequirementsChecker a PreloadCheck.

extensions/strings/extensions_strings.grd

 <?xml version="1.0" encoding="utf-8"?>
 
 <!--
   Strings for the extensions module. Used mostly for low-level error messages.
   Where possible new strings should be kept in Chrome and the extensions module
   should return an error code, message flag, etc.
 -->
 
 <grit latest_public_release="0" current_release="1"
       output_all_resource_defines="false" source_lang_id="en" enc_check="möl">
@@ skipping 290 matching lines @@
         This extension failed to name the download "<ph name="ATTEMPTED_FILENAME">$1<ex>apple.png</ex></ph>" because another extension (<ph name="EXTENSION_NAME">$2<ex>My Cool Extension</ex></ph>) determined a different filename "<ph name="ACTUAL_FILENAME">$3<ex>banana.png</ex></ph>".
       </message>
       <message name="IDS_EXTENSION_WARNING_RELOAD_TOO_FREQUENT" desc="Warning message which indates that an extension got stuck in a reload loop.">
         This extension reloaded itself too frequently.
       </message>
 
       <!-- Install related messages. Please keep alphabetized. -->
       <message name="IDS_EXTENSION_INSTALL_PROCESS_CRASHED" desc="Error message in case package fails to install because a utility process crashed.">
         Could not install package because a utility process crashed. Try restarting Chrome and trying again.
       </message>
+      <if expr="is_posix and not is_macosx">
+        <message name="IDS_EXTENSION_NPAPI_NOT_SUPPORTED" desc="Error message when an extension has a requirement for plugins that the system does not support.">
+          NPAPI plugins are not supported.
+        </message>
+      </if>
       <message name="IDS_EXTENSION_PACKAGE_ERROR_CODE" desc="Error message in cases where we fail to install the extension because the crx file is invalid. For example, because the crx header or signature is invalid.">
         Package is invalid: '<ph name="ERROR_CODE">$1<ex>error</ex></ph>'.
       </message>
       <message name="IDS_EXTENSION_PACKAGE_ERROR_MESSAGE" desc="The cases where we get an error message string back from some other component. The message might be in English, but these are typically developer errors, and the extension SDK is English.">
         Package is invalid. Details: '<ph name="ERROR_MESSAGE">$1<ex>error</ex></ph>'.
       </message>
       <message name="IDS_EXTENSION_PACKAGE_INSTALL_ERROR" desc="Error message in case package fails to install because of some problem with the filesystem.">
         Could not install package: '<ph name="ERROR_CODE">$1<ex>error</ex></ph>'
       </message>
       <if expr="is_win">
         <message name="IDS_EXTENSION_UNPACK_FAILED" desc="On windows, it is possible to mount a disk without the root of that disk having a drive letter.  The sandbox does not support this. See crbug/49530 .">
           Can not unpack extension.  To safely unpack an extension, there must be a path to your profile directory that starts with a drive letter and does not contain a junction, mount point, or symlink.  No such path exists for your profile.
         </message>
       </if>
       <if expr="not is_win">
         <message name="IDS_EXTENSION_UNPACK_FAILED" desc="">
           Can not unpack extension.  To safely unpack an extension, there must be a path to your profile directory that does not contain a symlink.  No such path exists for your profile.
         </message>
       </if>
+      <message name="IDS_EXTENSION_WEBGL_NOT_SUPPORTED" desc="Error message when an extension has a requirement for WebGL that the system does not support.">
+        WebGL is not supported.
+      </message>
+      <if expr="not use_aura">
+        <message name="IDS_EXTENSION_WINDOW_SHAPE_NOT_SUPPORTED" desc="Error message when an extension has a requirement for shaped windows that the system does not support.">
+          Shaped windows are not supported.
+        </message>
+      </if>
 
       <!-- Utility process names. Please keep alphabetized. -->
       <message name="IDS_UTILITY_PROCESS_EXTENSION_UNPACKER_NAME" desc="The name of the utility process used for unpacking extensions.">
         Extension Unpacker
       </message>
       <message name="IDS_UTILITY_PROCESS_MANIFEST_PARSER_NAME" desc="The name of the utility process used for parsing extension manifests.">
         Extension Manifest Parser
       </message>
     </messages>
   </release>
 </grit>