Add WebAPK installation metrics.

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 801e24be44dacc908e78e404f740d53b5acbddfc..407990bf4828ff8bb264809934c7cadc9fc84556 100644
--- a/chrome/browser/android/banners/app_banner_infobar_delegate_android.h
+++ b/chrome/browser/android/banners/app_banner_infobar_delegate_android.h
@@ -27,6 +27,14 @@ struct ShortcutInfo;
 
 namespace banners {
 
+// The states of WebAPK installation process. These states are tracked to
+// record dismiss events for WebAPK installation.
+enum InstallState {

[dominickn, 2016/09/05 07:34:31]

This enum should be in webapk_metrics.h

[Xi Han, 2016/09/07 20:58:52]

Done.

+  WAIT_FOR_START,
+  INSTALLING,
+  INSTALLED,
+};
+
 // Manages installation of an app being promoted by a page.
 class AppBannerInfoBarDelegateAndroid : public ConfirmInfoBarDelegate {
  public:
@@ -113,6 +121,8 @@ class AppBannerInfoBarDelegateAndroid : public ConfirmInfoBarDelegate {
 
   std::string webapk_package_name_;
   bool is_webapk_;
+  // Indicates the current state of a WebAPK installation.
+  InstallState install_state_;
 
   base::WeakPtrFactory<AppBannerInfoBarDelegateAndroid> weak_ptr_factory_;