Standardize usage of virtual/override/final in device/

The Google C++ style guide states:

  Explicitly annotate overrides of virtual functions or virtual
  destructors with an override or (less frequently) final specifier.
  Older (pre-C++11) code will use the virtual keyword as an inferior
  alternative annotation. For clarity, use exactly one of override,
  final, or virtual when declaring an override.

To better conform to these guidelines, the following constructs have
been rewritten:

- if a base class has a virtual destructor, then:
    virtual ~Foo();                   ->  ~Foo() override;
- virtual void Foo() override;        ->  void Foo() override;
- virtual void Foo() override final;  ->  void Foo() final;

This patch was automatically generated. The clang plugin can generate
fixit hints, which are suggested edits when it is 100% sure it knows how
to fix a problem. The hints from the clang plugin were applied to the
source tree using the tool in https://codereview.chromium.org/598073004.

BUG=417463
TBR=keybuk@chromium.org

Review URL: https://codereview.chromium.org/663203007

Cr-Commit-Position: refs/heads/master@{#300790}

1 files changed, 3 insertions, 3 deletions

diff --git a/device/serial/data_receiver.h b/device/serial/data_receiver.h
index df37018..79121f7 100644
--- a/device/serial/data_receiver.h
+++ b/device/serial/data_receiver.h
@@ -43,14 +43,14 @@ class DataReceiver : public base::RefCounted<DataReceiver>,
   struct PendingError;
   friend class base::RefCounted<DataReceiver>;
 
-  virtual ~DataReceiver();
+  ~DataReceiver() override;
 
   // serial::DataSourceClient override. Invoked by the DataSource to report
   // errors.
-  virtual void OnError(uint32_t bytes_since_last_error, int32_t error) override;
+  void OnError(uint32_t bytes_since_last_error, int32_t error) override;
 
   // mojo::ErrorHandler override. Calls ShutDown().
-  virtual void OnConnectionError() override;
+  void OnConnectionError() override;
 
   // Invoked by the PendingReceive to report that the user is done with the
   // receive buffer, having read |bytes_read| bytes from it.