Remove the app banner navigation heuristic.

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 20bff4cce5498300ed8d62446cfa00b5ceac347c..41f88340aa640ed7c3cfff1b9bb95395d5f7ab41 100644
--- a/chrome/browser/banners/app_banner_manager.h
+++ b/chrome/browser/banners/app_banner_manager.h
@@ -58,11 +58,8 @@ class AppBannerManager : public content::WebContentsObserver,
   // Fast-forwards the current time for testing.
   static void SetTimeDeltaForTesting(int days);
 
-  // Sets the weights applied to direct and indirect navigations for triggering
-  // the banner. Deprecated and will be removed when app banners fully migrates
-  // to using site engagement as a trigger.
-  static void SetEngagementWeights(double direct_engagement,
-                                   double indirect_engagement);
+  // Sets the total engagement required for triggering the banner in testing.
+  static void SetTotalEngagementToTrigger(double engagement);
 
   // Returns whether or not the URLs match for everything except for the ref.
   static bool URLsAreForTheSamePage(const GURL& first, const GURL& second);
@@ -160,9 +157,8 @@ class AppBannerManager : public content::WebContentsObserver,
 
   // Sends a message to the renderer that the page has met the requirements to
   // show a banner. The page can respond to cancel the banner (and possibly
-  // display it later), or otherwise allow it to be shown. This is virtual to
-  // allow tests to mock out the renderer IPC.
-  virtual void SendBannerPromptRequest();
+  // display it later), or otherwise allow it to be shown.
+  void SendBannerPromptRequest();
 
   // content::WebContentsObserver overrides.
   void DidStartNavigation(content::NavigationHandle* handle) override;