Decouple input_method from BrowserThread (and content/).

chrome/browser/chromeos/input_method/input_method_delegate.h

 // Copyright (c) 2012 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 CHROME_BROWSER_CHROMEOS_INPUT_METHOD_INPUT_METHOD_DELEGATE_H_
 #define CHROME_BROWSER_CHROMEOS_INPUT_METHOD_INPUT_METHOD_DELEGATE_H_
 
 #include <string>
 
 #include "base/basictypes.h"
+#include "base/memory/ref_counted.h"
+
+namespace base {
+class SequencedTaskRunner;
+}  // namespace base
 
 namespace chromeos {
 namespace input_method {
 
 // Provides access to read/persist Input Method-related properties.
 class InputMethodDelegate {
  public:
   InputMethodDelegate() {}
   virtual ~InputMethodDelegate() {}
 
   // Retrieves the hardware keyboard layout ID. May return an empty string if
   // the ID is unknown.
   virtual std::string GetHardwareKeyboardLayout() const = 0;
   // Retrieves the currently active UI locale.
   virtual std::string GetActiveLocale() const = 0;
+  // Retrieves the default task runner. The public input_method API should only
+  // be accessed in the context of this task runner.
+  virtual scoped_refptr<base::SequencedTaskRunner>
+      GetDefaultTaskRunner() const = 0;
+  // Retrieves a task runner that may be used for possibly blocking tasks such
+  // as file IO.
+  virtual scoped_refptr<base::SequencedTaskRunner>
+      GetWorkerTaskRunner() const = 0;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(InputMethodDelegate);
 };
 
 }  // namespace input_method
 }  // namespace chromeos
 
 #endif  // CHROME_BROWSER_CHROMEOS_INPUT_METHOD_INPUT_METHOD_DELEGATE_H_