Update web-platform-tests docs

docs/testing/test_browser_dialog.md

 # Testing Chrome browser dialogs with TestBrowserDialog
 
 \#include "[chrome/browser/ui/test/test_browser_dialog.h]"
 
 `TestBrowserDialog` provides a way to register an `InProcessBrowserTest` testing
 harness with a framework that invokes Chrome browser dialogs in a consistent
 way. It optionally provides a way to invoke dialogs "interactively". This allows
 screenshots to be generated easily, with the same test data, to assist with UI
 review. It also provides a registry of dialogs so they can be systematically
 checked for subtle changes and regressions.
@@ skipping 31 matching lines @@
 IN_PROC_BROWSER_TEST_F(FooDialogTest, InvokeDialog_default) {
   RunDialog();
 }
 ```
 
 Notes:
 
 *   The body of the test is always just "`RunDialog();`".
 *   "`default`" is the `std::string` passed to `ShowDialog()` and can be
     customized. See
-    [Testing additional dialog "styles"](#Testing-additional-dialog-styles_).
+    [Testing additional dialog "styles"](#Testing-additional-dialog-styles).
 *   The text before `default` (in this case) must always be "`InvokeDialog_`".
 
 ### Concrete examples
 
 *   [chrome/browser/ui/ask_google_for_suggestions_dialog_browsertest.cc]
 *   [chrome/browser/ui/autofill/card_unmask_prompt_view_browsertest.cc]
 *   [chrome/browser/ui/collected_cookies_browsertest.cc]
 *   [chrome/browser/ui/update_chrome_dialog_browsertest.cc]
 
 ##  Running the tests
@@ skipping 207 matching lines @@
  * should remain open until the dialog is dismissed
  */
 ```
 
 [chrome/browser/ui/test/test_browser_dialog.h]: https://cs.chromium.org/chromium/src/chrome/browser/ui/test/test_browser_dialog.h
 [chrome/browser/ui/autofill/card_unmask_prompt_view_browsertest.cc]: https://cs.chromium.org/chromium/src/chrome/browser/ui/autofill/card_unmask_prompt_view_browsertest.cc?l=104&q=ShowDialog
 [chrome/browser/ui/collected_cookies_browsertest.cc]: https://cs.chromium.org/chromium/src/chrome/browser/ui/collected_cookies_browsertest.cc?l=26&q=ShowDialog
 [chrome/browser/ui/ask_google_for_suggestions_dialog_browsertest.cc]: https://cs.chromium.org/chromium/src/chrome/browser/ui/ask_google_for_suggestions_dialog_browsertest.cc?l=18&q=ShowDialog
 [chrome/browser/ui/update_chrome_dialog_browsertest.cc]: https://cs.chromium.org/chromium/src/chrome/browser/ui/update_chrome_dialog_browsertest.cc?l=15&q=ShowDialog
 [ExtensionBrowserTest]: https://cs.chromium.org/chromium/src/chrome/browser/extensions/extension_browsertest.h?q=extensionbrowsertest&l=40