Move polyfill JavaScript code to be included as a remote script from …

[jonathanKingston]

Description

Inline <script tags are a source of code injection, the browser can protect against this with CSP to block inline scripts. However Magento has a lot of inline scripts that need removing bit-by-bit.

Fixed Issues (if relevant)

1. Removal of an inline script block

Manual testing scenarios

1. Ensure browsers with no localstorage still support storage

Contribution checklist

• Pull request has a meaningful description of its purpose
• All commits are accompanied by meaningful commit messages
• All new or changed code is covered with unit/integration tests (if applicable)
• All automated tests passed successfully (all builds on Travis CI are green)

[jonathanKingston]

Updating to fix the coding style since it was moved...

[jonathanKingston]

Updated code style which is now passing locally.

[VladimirZaets]

Hi @jonathanKingston. Please fix it using the backward compatible way. We can't delete block from the layout. Please look at our document for more details about backward compatibility. You can leave the block declaration, and use <script type="text/x-magento-init"> to initialize js file.

[jonathanKingston]

@VladimirZaets I'm a little confused by your comment, this should be fully backwards compatible no? If I use an init block it will be asynchronously loaded where as this will load synchronously in the same manner as the embedded block currently.
Are you suggesting that the app/code/Magento/Theme/view/frontend/templates/js/polyfill.phtml file should still exist? If so the only way would be for this to import the new JS file I have created.

[VladimirZaets]

@jonathanKingston We had discussion about this case and take desition that your fix is ok, so we will merge your fix in the near time, thanks.

[magento-engcom-team]

Hi @jonathanKingston. Thank you for your contribution.
Changes from your Pull Request will be available with the upcoming 2.3.0 release.