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..b0fb07b5609450ea57ace8316fa4e4e24dab2506 100644
--- a/chrome/browser/android/banners/app_banner_infobar_delegate_android.h
+++ b/chrome/browser/android/banners/app_banner_infobar_delegate_android.h
@@ -11,7 +11,6 @@
 #include "base/strings/string16.h"
 #include "chrome/browser/banners/app_banner_manager.h"
 #include "components/infobars/core/confirm_infobar_delegate.h"
-#include "content/public/common/manifest.h"
 #include "ui/gfx/image/image.h"
 #include "url/gurl.h"
 
@@ -24,6 +23,7 @@ class InfoBarManager;
 }
 
 class AppBannerInfoBar;
+struct ShortcutInfo;
 
 namespace banners {
 
@@ -34,9 +34,7 @@ class AppBannerInfoBarDelegateAndroid : public ConfirmInfoBarDelegate {
   AppBannerInfoBarDelegateAndroid(

[Peter Kasting, 2016/09/06 19:31:23]

Infobar delegate classes shouldn't have public constructors.  The constructor
should be private, and there should be a public Create() function that
constructs the delegate and its infobar and adds the infobar to the relevant
infobar service.  A simple such example is at
GeneratedPasswordSavedInfoBarDelegateAndroid::Create().

[Xi Han, 2016/09/07 15:53:17]

Done.

       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<ShortcutInfo> info,

[Peter Kasting, 2016/09/06 19:31:23]

Why are you passing and storing this by unique_ptr instead of passing by const
ref and storing by value?  The lone caller of this constructor always passes a
non-null pointer, so this just obscures that.

[Xi Han, 2016/09/07 15:53:17]

Mostly because it is empty when the delegate is initialized for native app. In
|AppBannerInfoBarDelegateAndroid|, we could declare "ShortcutInfo shortcut_info"
or a unique_ptr. When initializing the delegate for native app, the
|shorcut_info| it is always empty since it is not used nor initialized. So I
could either introduce a default constructor for ShorcutInfo which doesn't have
one, or use unique_ptr for the empty case of native app. Personally I prefer to
use unique_ptr.

[Peter Kasting, 2016/09/08 04:56:56]

That makes sense for now.  It seems like this can change if the delegate is
split into pieces for the native versus web cases, so keep this change on the
list of things to consider doing then.

       std::unique_ptr<SkBitmap> icon,
       int event_request_id,
       bool is_webapk);
@@ -67,6 +65,12 @@ 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 +88,7 @@ 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_;
 
@@ -91,12 +96,10 @@ class AppBannerInfoBarDelegateAndroid : public ConfirmInfoBarDelegate {
   base::WeakPtr<AppBannerManager> weak_manager_;
 
   base::string16 app_title_;
-  GURL manifest_url_;
-  content::Manifest manifest_;
+  std::unique_ptr<ShortcutInfo> shortcut_info_;
 
   base::android::ScopedJavaGlobalRef<jobject> native_app_data_;
 
-  GURL icon_url_;
   std::unique_ptr<SkBitmap> icon_;
 
   std::string native_app_package_;