Implement experimental app banner flow.

chrome/browser/banners/app_banner_manager_browsertest.cc

Index: chrome/browser/banners/app_banner_manager_browsertest.cc
diff --git a/chrome/browser/banners/app_banner_manager_browsertest.cc b/chrome/browser/banners/app_banner_manager_browsertest.cc
index 4f014568e351a0d87b4934340dff02a7921bca5e..55d932f2c827e979073199e9c27c4d2d6f927113 100644
--- a/chrome/browser/banners/app_banner_manager_browsertest.cc
+++ b/chrome/browser/banners/app_banner_manager_browsertest.cc
@@ -71,8 +71,8 @@ class AppBannerManagerTest : public AppBannerManager {
  protected:
   // All calls to RequestAppBanner should terminate in one of Stop() (not
   // showing banner), UpdateState(State::PENDING_ENGAGEMENT) (waiting for
-  // sufficient engagement), or ShowBanner(). Override these methods to capture
-  // test status.
+  // sufficient engagement), or ShowBannerUI(). Override these methods to
+  // capture test status.
   void Stop() override {
     AppBannerManager::Stop();
     ASSERT_FALSE(will_show_.get());
@@ -80,7 +80,7 @@ class AppBannerManagerTest : public AppBannerManager {
     base::ThreadTaskRunnerHandle::Get()->PostTask(FROM_HERE, quit_closure_);
   }
 
-  void ShowBanner() override {
+  void ShowBannerUI() override {
     // Fake the call to ReportStatus here - this is usually called in
     // platform-specific code which is not exposed here.
     ReportStatus(nullptr, SHOWING_WEB_APP_BANNER);