Remove document_url metadata from Sentry reports

This has been replaced by the `hostURL` value in the `host_config`
metadata, which comes from the `#config` fragment. The `hostURL` value
should always contain the full URL, whereas `document_url` gets
truncated to the origin in many browsers. Also the term `hostURL` more
accurately reflects what the value is, since it may be different than
the document for which the client is displaying annotations.

src/sidebar/util/sentry.js

@@ -109,13 +109,6 @@ export function init(config) {
     // Ignore errors parsing configuration.
   }
 
-  // In the sidebar application, it is often useful to know the URL which the
-  // client was loaded into. This information is usually available in an iframe
-  // via `document.referrer`. More information about the document is available
-  // later when frames where the "annotator" code has loaded have connected to
-  // the sidebar via `postMessage` RPC messages.
-  Sentry.setExtra('document_url', document.referrer);
-
   /** @param {HTMLScriptElement} script */
   const isJavaScript = script =>
     !script.type || script.type.match(/javascript|module/);

src/sidebar/util/test/sentry-test.js

@@ -125,15 +125,6 @@ describe('sidebar/util/sentry', () => {
       assert.neverCalledWith(fakeSentry.setExtra, 'host_config');
     });
 
-    it('adds "document_url" context to reports', () => {
-      sentry.init({ dsn: 'test-dsn', environment: 'dev' });
-      assert.calledWith(
-        fakeSentry.setExtra,
-        'document_url',
-        'https://example.com'
-      );
-    });
-
     it('adds "loaded_scripts" context to reports', () => {
       sentry.init({ dsn: 'test-dsn', environment: 'dev' });
       assert.calledWith(fakeSentry.setExtra, 'loaded_scripts');