Trigger app banner when add to homescreen is pressed and WebAPKs are enabled.

chrome/browser/android/banners/app_banner_infobar_delegate_android.h

Index: chrome/browser/android/banners/app_banner_infobar_delegate_android.h
diff --git a/chrome/browser/android/banners/app_banner_infobar_delegate_android.h b/chrome/browser/android/banners/app_banner_infobar_delegate_android.h
index c78aa8def8af41f30db46695348dfc8db65437ab..886bb122b80c74d3a3617e2cb750de9a0b9374e9 100644
--- a/chrome/browser/android/banners/app_banner_infobar_delegate_android.h
+++ b/chrome/browser/android/banners/app_banner_infobar_delegate_android.h
@@ -24,6 +24,7 @@ class InfoBarManager;
 }
 
 class AppBannerInfoBar;
+struct ShortcutInfo;
 
 namespace banners {
 
@@ -35,6 +36,17 @@ class AppBannerInfoBarDelegateAndroid : public ConfirmInfoBarDelegate {
       base::WeakPtr<AppBannerManager> weak_manager,
       const base::string16& app_title,
       const GURL& manifest_url,
+      std::unique_ptr<ShortcutInfo> info,
+      const GURL& icon_url,
+      std::unique_ptr<SkBitmap> icon,
+      int event_request_id,
+      bool is_webapk);
+
+  // Delegate for promoting a web app.
+  AppBannerInfoBarDelegateAndroid(
+      base::WeakPtr<AppBannerManager> weak_manager,
+      const base::string16& app_title,
+      const GURL& manifest_url,
       const content::Manifest& manifest,
       const GURL& icon_url,
       std::unique_ptr<SkBitmap> icon,
@@ -67,6 +79,12 @@ class AppBannerInfoBarDelegateAndroid : public ConfirmInfoBarDelegate {
                          const base::android::JavaParamRef<jobject>& obj,
                          jboolean success);
 
+  // Called when user clicks the "Add To Homescreen" from the app menu to
+  // install a WebAPK. This function sets the text on infobar to "Adding" and
+  // disables the button to avoid user interaction. It also starts the WebAPK's
+  // installation process automatically.
+  void InstallWebApk(content::WebContents* web_contents);
+
  private:
   void CreateJavaDelegate();
   bool AcceptNativeApp(content::WebContents* web_contents);
@@ -84,6 +102,7 @@ class AppBannerInfoBarDelegateAndroid : public ConfirmInfoBarDelegate {
   int GetButtons() const override;
   bool Accept() override;
   bool LinkClicked(WindowOpenDisposition disposition) override;
+  AppBannerInfoBarDelegateAndroid* AsAppBannerInfoBarDelegateAndroid() override;
 
   base::android::ScopedJavaGlobalRef<jobject> java_delegate_;
 
@@ -92,7 +111,7 @@ class AppBannerInfoBarDelegateAndroid : public ConfirmInfoBarDelegate {
 
   base::string16 app_title_;
   GURL manifest_url_;
-  content::Manifest manifest_;
+  std::unique_ptr<ShortcutInfo> shortcut_info_;
 
   base::android::ScopedJavaGlobalRef<jobject> native_app_data_;