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_mac.h

@@ -22,13 +22,13 @@ class TempWindowMac {
  private:
   // A single instance will be created/owned by RootWindowManager.
   friend class RootWindowManager;
-  // Allow deletion via scoped_ptr only.
-  friend struct base::DefaultDeleter<TempWindowMac>;
+  // Allow deletion via std::unique_ptr only.
+  friend std::default_delete<TempWindowMac>;
 
   TempWindowMac();
   ~TempWindowMac();
 
-  scoped_ptr<TempWindowMacImpl> impl_;
+  std::unique_ptr<TempWindowMacImpl> impl_;
 
   DISALLOW_COPY_AND_ASSIGN(TempWindowMac);
 };