Various fixes related to the C++11/14 update (see issue #3140)

- Convert scoped_ptr to std::unique_ptr from <memory>
- Convert arraysize to base::size from include/base/cef_cxx17_backports.h
- Convert NULL to nullptr
- Include include/base/cef_callback.h instead of include/base/cef_bind.h
- Implicit conversion of CefRefPtr<T> or scoped_refptr<T> to T* is gone;
  use .get() instead

See the issue for additional details.

tests/cefclient/browser/temp_window_win.h

@@ -20,8 +20,8 @@ class TempWindowWin {
  private:
   // A single instance will be created/owned by RootWindowManager.
   friend class RootWindowManager;
-  // Allow deletion via scoped_ptr only.
-  friend struct base::DefaultDeleter<TempWindowWin>;
+  // Allow deletion via std::unique_ptr only.
+  friend std::default_delete<TempWindowWin>;
 
   TempWindowWin();
   ~TempWindowWin();