Remove Task inheritance in clipboard code.

ui/base/clipboard/clipboard_mac.mm

 // 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.
 
 #include "ui/base/clipboard/clipboard.h"
 
 #import <Cocoa/Cocoa.h>
 
 #include "base/file_path.h"
 #include "base/logging.h"
@@ skipping 37 matching lines @@
 }
 
 void Clipboard::WriteObjects(const ObjectMap& objects) {
   NSPasteboard* pb = GetPasteboard();
   [pb declareTypes:[NSArray array] owner:nil];
 
   for (ObjectMap::const_iterator iter = objects.begin();
        iter != objects.end(); ++iter) {
     DispatchObject(static_cast<ObjectType>(iter->first), iter->second);
   }
-
 }
 
 void Clipboard::WriteText(const char* text_data, size_t text_len) {
   std::string text_str(text_data, text_len);
   NSString *text = base::SysUTF8ToNSString(text_str);
   NSPasteboard* pb = GetPasteboard();
   [pb addTypes:[NSArray arrayWithObject:NSStringPboardType] owner:nil];
   [pb setString:text forType:NSStringPboardType];
 }
 
@@ skipping 306 matching lines @@
 Clipboard::FormatType Clipboard::GetBitmapFormatType() {
   return base::SysNSStringToUTF8(NSTIFFPboardType);
 }
 
 // static
 Clipboard::FormatType Clipboard::GetWebKitSmartPasteFormatType() {
   return base::SysNSStringToUTF8(kWebSmartPastePboardType);
 }
 
 }  // namespace ui