Implement clipboard for aura and re-enable clipboard_unittests.

ui/base/clipboard/clipboard.h

 // Copyright (c) 2011 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_H_
 #define UI_BASE_CLIPBOARD_CLIPBOARD_H_
 #pragma once
 
 #include <map>
 #include <string>
@@ skipping 109 matching lines @@
   void WriteObjects(const ObjectMap& objects);
 
   // Behaves as above. If there is some shared memory handle passed as one of
   // the objects, it came from the process designated by |process|. This will
   // assist in turning it into a shared memory region that the current process
   // can use.
   void WriteObjects(const ObjectMap& objects, base::ProcessHandle process);
 
   // On Linux/BSD, we need to know when the clipboard is set to a URL.  Most
   // platforms don't care.
-#if defined(OS_WIN) || defined(OS_MACOSX)
+#if defined(OS_WIN) || defined(OS_MACOSX) || defined(USE_AURA)
   void DidWriteURL(const std::string& utf8_text) {}
 #else  // !defined(OS_WIN) && !defined(OS_MACOSX)
   void DidWriteURL(const std::string& utf8_text);
 #endif
 
   // Tests whether the clipboard contains a certain format
   bool IsFormatAvailable(const FormatType& format, Buffer buffer) const;
 
   // As above, but instead of interpreting |format| by some platform-specific
   // definition, interpret it as a literal MIME type.
@@ skipping 148 matching lines @@
   static const char kMimeTypeText[];
   static const char kMimeTypeHTML[];
   static const char kMimeTypePNG[];
 
   DISALLOW_COPY_AND_ASSIGN(Clipboard);
 };
 
 }  // namespace ui
 
 #endif  // UI_BASE_CLIPBOARD_CLIPBOARD_H_