[Smart Lock] Auto sign-in snackbar UI.

chrome/browser/ui/android/snackbars/auto_signin_snackbar_controller.h

+// Copyright 2015 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file
+
+#ifndef CHROME_BROWSER_UI_ANDROID_SNACKBARS_AUTO_SIGNIN_SNACKBAR_CONTROLLER_H_
+#define CHROME_BROWSER_UI_ANDROID_SNACKBARS_AUTO_SIGNIN_SNACKBAR_CONTROLLER_H_
+
+#include <jni.h>
+
+#include "base/android/scoped_java_ref.h"
+#include "base/strings/string16.h"
+
+namespace autofill {
+struct PasswordForm;
+}
+
+class TabAndroid;
+
+class AutoSigninSnackbarController {

[newt (away), 2015/08/21 05:40:39]

It appears you don't actually need a native AutoSigninSnackbarController object.
You could just have a single static method in C++:

  void ShowAutoSigninSnackbar(TabAndroid *tab, const base::string16 &username) {
    // call a static Java method to show the snackbar
  }

Then in Java, you'd have a method

  @CalledByNative
  private void showAutoSigninSnackbar(Tab tab, String username) {
    // create a controller and show the snackbar
  }

This would simplify things and avoid the tricky Java/C++ memory management.

[melandory, 2015/08/21 09:41:15]

Done.

+public:
+  explicit AutoSigninSnackbarController(TabAndroid *tab);
+  ~AutoSigninSnackbarController();
+
+  void onShow(const base::string16 &username);
+
+  void Destroy(JNIEnv *env, jobject obj);
+
+private:
+  base::android::ScopedJavaGlobalRef<jobject> java_snackbar_controller_;
+};
+
+// Registers native methods.
+bool RegisterAutoSigninSnackbarController(JNIEnv *env);
+
+#endif // CHROME_BROWSER_UI_ANDROID_SNACKBARS_AUTO_SIGNIN_SNACKBAR_CONTROLLER_H_