Chrome talks to Play to install WebAPKs.

chrome/browser/android/webapk/webapk_installer.h

Index: chrome/browser/android/webapk/webapk_installer.h
diff --git a/chrome/browser/android/webapk/webapk_installer.h b/chrome/browser/android/webapk/webapk_installer.h
index c24a66886f1d919d5d86d9a41f6c0baaeb25b304..4001fb97cafbe0a45d115646fe18f03aaec68233 100644
--- a/chrome/browser/android/webapk/webapk_installer.h
+++ b/chrome/browser/android/webapk/webapk_installer.h
@@ -105,6 +105,9 @@ class WebApkInstaller : public net::URLFetcherDelegate {
       JNIEnv* env,
       const base::android::ScopedJavaLocalRef<jstring>& java_file_path);
 
+  // Returns whether installing WebAPKs using Google Play is enabled.
+  virtual bool HasGooglePlayWebApkInstallDelegate();
+
   // Called when the request to install the WebAPK is sent to Google Play.
   void OnSuccess();
 
@@ -143,6 +146,12 @@ class WebApkInstaller : public net::URLFetcherDelegate {
   void SendRequest(std::unique_ptr<webapk::WebApk> request_proto,
                    const GURL& server_url);
 
+  // Called when the package name of the WebAPK is available and the install
+  // or update request is handled by Google Play.
+  void InstallOrUpdateWebApkFromGooglePlay(const std::string& package_name,
+                                           int version,
+                                           const std::string& token);
+
   // Called with the URL of generated WebAPK and the package name that the
   // WebAPK should be installed at.
   void OnGotWebApkDownloadUrl(const GURL& download_url,