Bug 1715012 - [devtools] Use gBrowser.reloadTab in navigateTo when the provided URL is the same as the current one. r=ochameau.

In Bug 1710582, `refreshTab` switched to use `navigateTo` in order to handle target switching.
The catch is that `navigateTo` uses `BrowserTestUtils.loadURI`, which triggers a slightly
different behavior than `gBrowser.reloadTab` (for example, it does not keep the scroll position).
In this patch, we modify `navigateTo` so it uses `reloadTab` if the URL provided for
the navigation is the same as the current one.

Differential Revision: https://phabricator.services.mozilla.com/D117018

devtools/client/shared/test/shared-head.js

@@ -499,7 +499,14 @@ async function navigateTo(uri, { isErrorPage = false } = {}) {
     },
     isErrorPage
   );
-  BrowserTestUtils.loadURI(browser, uri);
+
+  // if we're navigating to the same page we're already on, use reloadTab instead as the
+  // behavior slightly differs from loadURI (e.g. scroll position isn't keps with the latter).
+  if (uri === browser.currentURI.spec) {
+    gBrowser.reloadTab(gBrowser.selectedTab);
+  } else {
+    BrowserTestUtils.loadURI(browser, uri);
+  }
 
   info(`Waiting for page to be loaded…`);
   await onBrowserLoaded;