Revert 111080 - Remove Task inheritance in clipboard code.

content/browser/renderer_host/clipboard_message_filter.cc

Index: content/browser/renderer_host/clipboard_message_filter.cc
===================================================================
--- content/browser/renderer_host/clipboard_message_filter.cc	(revision 111082)
+++ content/browser/renderer_host/clipboard_message_filter.cc	(working copy)
@@ -11,7 +11,6 @@
 #endif
 
 #include "base/bind.h"
-#include "base/bind_helpers.h"
 #include "base/stl_util.h"
 #include "content/common/clipboard_messages.h"
 #include "content/public/browser/content_browser_client.h"
@@ -25,13 +24,25 @@
 
 namespace {
 
-// This helper is needed because content::ContentBrowserClient::GetClipboard()
-// must be called on the UI thread.
-void WriteObjectsHelper(const ui::Clipboard::ObjectMap* objects) {
-  content::GetContentClient()->browser()->GetClipboard()->WriteObjects(
-      *objects);
-}
+// Completes a clipboard write initiated by the renderer. The write must be
+// performed on the UI thread because the clipboard service from the IO thread
+// cannot create windows so it cannot be the "owner" of the clipboard's
+// contents.
+class WriteClipboardTask : public Task {
+ public:
+  explicit WriteClipboardTask(ui::Clipboard::ObjectMap* objects)
+      : objects_(objects) {}
+  ~WriteClipboardTask() {}
 
+  void Run() {
+    content::GetContentClient()->browser()->GetClipboard()->WriteObjects(
+        *objects_.get());
+  }
+
+ private:
+  scoped_ptr<ui::Clipboard::ObjectMap> objects_;
+};
+
 }  // namespace
 
 ClipboardMessageFilter::ClipboardMessageFilter() {
@@ -93,7 +104,7 @@
   BrowserThread::PostTask(
       BrowserThread::UI,
       FROM_HERE,
-      base::Bind(&WriteObjectsHelper, base::Owned(long_living_objects)));
+      new WriteClipboardTask(long_living_objects));
 }
 
 void ClipboardMessageFilter::OnWriteObjectsAsync(
@@ -111,7 +122,7 @@
   BrowserThread::PostTask(
       BrowserThread::UI,
       FROM_HERE,
-      base::Bind(&WriteObjectsHelper, base::Owned(long_living_objects)));
+      new WriteClipboardTask(long_living_objects));
 }
 
 void ClipboardMessageFilter::OnGetSequenceNumber(