Add a new WebAPK-specific app banner shortcut source.

chrome/browser/android/banners/app_banner_infobar_delegate_android.cc

Index: chrome/browser/android/banners/app_banner_infobar_delegate_android.cc
diff --git a/chrome/browser/android/banners/app_banner_infobar_delegate_android.cc b/chrome/browser/android/banners/app_banner_infobar_delegate_android.cc
index c0b69b8270aa85d7f07b074489deaec14d67ba4f..053b497382bfe36485907f471b5609afb15df042 100644
--- a/chrome/browser/android/banners/app_banner_infobar_delegate_android.cc
+++ b/chrome/browser/android/banners/app_banner_infobar_delegate_android.cc
@@ -227,6 +227,11 @@ AppBannerInfoBarDelegateAndroid::AppBannerInfoBarDelegateAndroid(
       webapk_install_source_(webapk_install_source),
       weak_ptr_factory_(this) {
   DCHECK(!IsInfoEmpty(shortcut_info_));
+
+  // Explicitly update the source to separate WebAPKs installed from the banner
+  // from legacy PWAs that are installed from the banner.
+  if (is_webapk && webapk_install_source == webapk::INSTALL_SOURCE_BANNER)
+    shortcut_info_->UpdateSource(ShortcutInfo::SOURCE_APP_BANNER_WEBAPK);

[pkotwicz, 2017/04/12 15:46:01]

I would rather if this code was in AppBannerManagerAndroid

That's where we set ShortcutInfo::SOURCE_APP_BANNER too

We would need to plumb |is_webapk| to AppBannerInfoBarDelegateAndroid::Create()

[dominickn, 2017/05/03 00:26:04]

I'd rather keep WebAPK specific code in here. Soon enough we'll either need to
split apart AppBannerInfoBarDelegateAndroid into a WebAPK version and legacy
version, or we'll entirely remove legacy PWA shortcuts and thus everything in
here will be WebAPKs only. It will be much easier to do that if all of the
WebAPK-specific code is isolated in here.

[Xi Han, 2017/05/03 18:07:50]

AppBannerManagerAndroid has the |can_install_webapk_| that already checked
whether it is WebAPK, so we can set the source there without plumbing the
|is_webapk| to AppBannerInfoBarDelegateAndroid::Create(). I don't have a strong
preference, but it is nice to set it ASAP. Dom, it is up to you:)

[dominickn, 2017/05/04 00:33:59]

Hmm, that's true. I forgot about that member entirely. I'll move it there then.

   CreateJavaDelegate();
 }