Skip installation process if WebAPK is already installed.

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 36a65e3cdc4cce17f59af8862fd119465b0805fa..1ce9874a5b97b8d4416ec86cba3494bda2eb1656 100644
--- a/chrome/browser/android/banners/app_banner_infobar_delegate_android.cc
+++ b/chrome/browser/android/banners/app_banner_infobar_delegate_android.cc
@@ -38,6 +38,8 @@ using base::android::ConvertUTF16ToJavaString;
 using base::android::JavaParamRef;
 using base::android::ScopedJavaLocalRef;
 
+// TODO(zpeng): Reorganize control flow to allow itemized metrics.

[dominickn, 2016/09/28 02:10:25]

Nit: don't have a TODO without a crbug link.

[F, 2016/09/30 18:02:01]

Done. Thanks for the information!

+
 namespace {
 
 bool IsInfoEmpty(const std::unique_ptr<ShortcutInfo>& info) {
@@ -194,26 +196,37 @@ bool AppBannerInfoBarDelegateAndroid::AcceptWebApk(
     return true;
   }
 
-  // Request install the WebAPK.
-  install_state_ = INSTALLING;
-  TrackUserResponse(USER_RESPONSE_WEB_APP_ACCEPTED);
-  AppBannerSettingsHelper::RecordBannerInstallEvent(
-      web_contents, shortcut_info_->url.spec(), AppBannerSettingsHelper::WEB);
+  // Check whether the WebAPK has been installed.
+  std::string installed_webapk_package_name =
+      ShortcutHelper::QueryWebApkPackage(web_contents->GetLastCommittedURL());
+  if (installed_webapk_package_name.empty()) {
+    // Request install the WebAPK.
+    install_state_ = INSTALLING;
+    TrackUserResponse(USER_RESPONSE_WEB_APP_ACCEPTED);
+    AppBannerSettingsHelper::RecordBannerInstallEvent(
+        web_contents, shortcut_info_->url.spec(), AppBannerSettingsHelper::WEB);
 
-  Java_AppBannerInfoBarDelegateAndroid_setWebApkInstallingState(
-      env, java_delegate_, true);
-  UpdateInstallState(env, nullptr);
-  WebApkInstaller::FinishCallback callback =
-      base::Bind(&AppBannerInfoBarDelegateAndroid::OnWebApkInstallFinished,
-                  weak_ptr_factory_.GetWeakPtr());
-  ShortcutHelper::InstallWebApkWithSkBitmap(web_contents->GetBrowserContext(),
-                                            *shortcut_info_,
-                                            *icon_.get(), callback);
-  SendBannerAccepted(web_contents, "web");
+    Java_AppBannerInfoBarDelegateAndroid_setWebApkInstallingState(
+        env, java_delegate_, true);
+    UpdateInstallState(env, nullptr);
+    WebApkInstaller::FinishCallback callback =
+        base::Bind(&AppBannerInfoBarDelegateAndroid::OnWebApkInstallFinished,
+                    weak_ptr_factory_.GetWeakPtr());
+    ShortcutHelper::InstallWebApkWithSkBitmap(web_contents->GetBrowserContext(),
+                                              *shortcut_info_,
+                                              *icon_.get(), callback);
+    SendBannerAccepted(web_contents, "web");
 
-  // Prevent the infobar from disappearing, because the infobar will show
-  // "Adding" during the installation process.
-  return false;
+    // Prevent the infobar from disappearing, because the infobar will show
+    // "Adding" during the installation process.
+    return false;
+  } else {

[dominickn, 2016/09/28 02:10:25]

Nit: remove the else clause (no else after return) - just have the contents
outside of the else.

[F, 2016/09/30 18:02:01]

Done. Thanks for the information!

+    // Bypass the installation process.
+    TrackUserResponse(USER_RESPONSE_WEB_APP_ACCEPTED);

[pkotwicz, 2016/09/29 14:18:54]

Shouldn't you log:
webapk::TrackUserAction(webapk::USER_ACTION_OPEN) instead of
TrackUserResponse(USER_RESPONSE_WEB_APP_ACCEPTED)

It is not clear that we shouldn't log the USER_RESPONSE_WEB_APP_ACCEPTED
histogram. It feels like the histogram should only be logged when the "user has
accepted a WebAPK install"

[F, 2016/09/30 18:02:01]

Resolved in offline discussion. Filed new issue
https://bugs.chromium.org/p/chromium/issues/detail?id=651615.

+    weak_ptr_factory_.GetWeakPtr()->OnWebApkInstallFinished(
+        true, installed_webapk_package_name);

[pkotwicz, 2016/09/29 14:18:54]

Calling AppBannerInfoBarDelegateAndroid::OnWebApkInstallFinished() is not
completely right because OnWebApkInstallFinished() logs the
INSTALL_EVENT_WEB_APP_INSTALLED metric (which in my opinion we do not want
because no installation took place)

My proposal is to move lines 406 - 414 to their own function:
SetCanOpenWebApk(const std::string& webapk_package_name)

[F, 2016/09/30 18:02:01]

Resolved in offline discussion. See above.

+    return false;
+  }
 }
 
 AppBannerInfoBarDelegateAndroid::AppBannerInfoBarDelegateAndroid(