Remove unused WebApkInstaller::Register()

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 35046dc8c18afb87d6682cae290dc546487ccb9f..c1ba56a76ad9aa5420648b65519e3a4decf58761 100644
--- a/chrome/browser/android/webapk/webapk_installer.h
+++ b/chrome/browser/android/webapk/webapk_installer.h
@@ -45,9 +45,6 @@ class WebApkInstaller : public net::URLFetcherDelegate {
                   const SkBitmap& shorcut_icon);
   ~WebApkInstaller() override;
 
-  // Register JNI methods.
-  static bool Register(JNIEnv* env);
-
   // Talks to the Chrome WebAPK server to generate a WebAPK on the server and to
   // Google Play to install the generated WebAPK. Calls |callback| after the
   // request to install the WebAPK is sent to Google Play.