Make Android Clipboard Keep Track of Last Modified Time

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>
@@ skipping 27 matching lines @@
                 std::string* src_url,
                 uint32_t* fragment_start,
                 uint32_t* 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;
+  base::Time GetClipboardLastModifiedTime() const override;
   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;
 
   DISALLOW_COPY_AND_ASSIGN(ClipboardAndroid);
 };
 
 }  // namespace ui
 
 #endif  // UI_BASE_CLIPBOARD_CLIPBOARD_ANDROID_H_