Change Clipboard to use virtual methods for testing purposes.

ui/base/clipboard/clipboard_android.h

+// Copyright 2014 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 UI_BASE_CLIPBOARD_CLIPBOARD_ANDROID_H_
+#define UI_BASE_CLIPBOARD_CLIPBOARD_ANDROID_H_
+
+#include "ui/base/clipboard/clipboard.h"
+
+#include <jni.h>
+
+namespace ui {
+
+bool RegisterClipboardAndroid(JNIEnv* env);
+
+class ClipboardAndroid : public Clipboard {
+ public:
+  ClipboardAndroid();
+  ~ClipboardAndroid() override;

[sky, 2014/10/16 19:40:11]

virtual and I don't believe we use override on destructors.

[dcheng, 2014/10/16 21:51:39]

The C++ style guide seems to be unambiguous on this point:
http://google-styleguide.googlecode.com/svn/trunk/cppguide.html

"Explicitly annotate overrides of virtual functions or virtual destructors with
an override or (less frequently) final specifier"

Avi brought this issue up to me as well when the clang plugin was updated in
https://codereview.chromium.org/597863002. I am inclined to follow the Google
C++ style guide on this point, in order to minimize the diffs between Chromium
and Google style.

+
+  // Clipboard public overrides:

[sky, 2014/10/16 19:40:11]

You could actually move all of this to private as in theory you shouldn't be
using ClipboardAndroid directly.

[dcheng, 2014/10/16 21:51:39]

Good point. Done. I've made everything private... because why not.

+  uint64 GetSequenceNumber(ClipboardType type) override;

[sky, 2014/10/16 19:40:11]

virtual on all of these.

[dcheng, 2014/10/16 21:51:38]

Style guide: "For clarity, use exactly one of override, final, or virtual when
declaring an override."

The plugin accepts (but does not require) this style now, and I'd like to save
myself some work down the road.

+  bool IsFormatAvailable(const FormatType& format,
+                         ClipboardType type) const override;
+  void Clear(ClipboardType type) override;
+  void ReadAvailableTypes(ClipboardType type,
+                          std::vector<base::string16>* types,
+                          bool* contains_filenames) const override;
+  void ReadText(ClipboardType type, base::string16* result) const override;
+  void ReadAsciiText(ClipboardType type, std::string* result) const override;
+  void ReadHTML(ClipboardType type,
+                base::string16* markup,
+                std::string* src_url,
+                uint32* fragment_start,
+                uint32* fragment_end) const override;
+  void ReadRTF(ClipboardType type, std::string* result) const override;
+  SkBitmap ReadImage(ClipboardType type) const override;
+  void ReadCustomData(ClipboardType clipboard_type,
+                      const base::string16& type,
+                      base::string16* result) const override;
+  void ReadBookmark(base::string16* title, std::string* url) const override;
+  void ReadData(const FormatType& format, std::string* result) const override;
+
+ protected:
+  // Clipboard protected overrides:
+  void WriteObjects(ClipboardType type, const ObjectMap& objects) override;
+  void WriteText(const char* text_data, size_t text_len) override;
+  void WriteHTML(const char* markup_data,
+                 size_t markup_len,
+                 const char* url_data,
+                 size_t url_len) override;
+  void WriteRTF(const char* rtf_data, size_t data_len) override;
+  void WriteBookmark(const char* title_data,
+                     size_t title_len,
+                     const char* url_data,
+                     size_t url_len) override;
+  void WriteWebSmartPaste() override;
+  void WriteBitmap(const SkBitmap& bitmap) override;
+  void WriteData(const FormatType& format,
+                 const char* data_data,
+                 size_t data_len) override;
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(ClipboardAndroid);
+};
+
+}  // namespace ui
+
+#endif  // UI_BASE_CLIPBOARD_CLIPBOARD_ANDROID_H_