Check if a PWA is installed before checking the service worker and icon.

chrome/browser/banners/app_banner_manager.h

Index: chrome/browser/banners/app_banner_manager.h
diff --git a/chrome/browser/banners/app_banner_manager.h b/chrome/browser/banners/app_banner_manager.h
index 4301ca903b99a83454f3f12ed044240079ad72e3..be43a915fbb21c84a08228aa77b0bf712d7976d4 100644
--- a/chrome/browser/banners/app_banner_manager.h
+++ b/chrome/browser/banners/app_banner_manager.h
@@ -104,6 +104,11 @@ class AppBannerManager : public content::WebContentsObserver,
   explicit AppBannerManager(content::WebContents* web_contents);
   ~AppBannerManager() override;
 
+  // Returns true if the banner should be shown. Returns false if the banner has
+  // been shown too recently, or if the app has already been installed.
+  // GetAppIdentifier() must return a valid value for this method to work.
+  bool CheckIfShouldShowBanner();
+
   // Return a string identifying this app for metrics.
   virtual std::string GetAppIdentifier();
 
@@ -221,9 +226,6 @@ class AppBannerManager : public content::WebContentsObserver,
   // platform-specific.
   virtual void ShowBanner() = 0;
 
-  // Returns true if the banner should be shown.
-  bool CheckIfShouldShowBanner();
-
   // Called after the manager sends a message to the renderer regarding its
   // intention to show a prompt. The renderer will send a message back with the
   // opportunity to cancel.