Revert of Remove dependency on content from remoting_host.

remoting/host/chromeos/clipboard_aura.h

Index: remoting/host/chromeos/clipboard_aura.h
diff --git a/remoting/host/chromeos/clipboard_aura.h b/remoting/host/chromeos/clipboard_aura.h
index e561e2eaa4317029998f9fd9198a2380677e7a06..9907fb6dfd8bbf8bf24d4d9602d1c98c1bf1f23d 100644
--- a/remoting/host/chromeos/clipboard_aura.h
+++ b/remoting/host/chromeos/clipboard_aura.h
@@ -6,8 +6,7 @@
 #define REMOTING_HOST_CLIPBOARD_AURA_H_
 
 #include "base/memory/scoped_ptr.h"
-#include "base/threading/thread_checker.h"
-#include "base/timer/timer.h"
+#include "base/single_thread_task_runner.h"
 #include "remoting/host/clipboard.h"
 
 namespace remoting {
@@ -26,9 +25,11 @@
 // The public API of this class can be called in any thread as internally it
 // always posts the call to the |ui_task_runner|.  On ChromeOS, that should
 // be the UI thread of the browser process.
+//
 class ClipboardAura : public Clipboard {
  public:
-  explicit ClipboardAura();
+  explicit ClipboardAura(
+      scoped_refptr<base::SingleThreadTaskRunner> ui_task_runner);
   ~ClipboardAura() override;
 
   // Clipboard interface.
@@ -40,13 +41,10 @@
   void SetPollingIntervalForTesting(base::TimeDelta polling_interval);
 
  private:
-  void CheckClipboardForChanges();
+  class Core;
 
-  base::ThreadChecker thread_checker_;
-  scoped_ptr<protocol::ClipboardStub> client_clipboard_;
-  base::RepeatingTimer<ClipboardAura> clipboard_polling_timer_;
-  uint64 current_change_count_;
-  base::TimeDelta polling_interval_;
+  scoped_ptr<Core> core_;
+  scoped_refptr<base::SingleThreadTaskRunner> ui_task_runner_;
 
   DISALLOW_COPY_AND_ASSIGN(ClipboardAura);
 };