Add the pdf plugin's source in src\pdf.

pdf/fading_control.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 PDF_FADING_CONTROL_H_
+#define PDF_FADING_CONTROL_H_
+
+#include "pdf/control.h"
+
+namespace chrome_pdf {
+
+class FadingControl : public Control {
+ public:
+  FadingControl();
+  virtual ~FadingControl();
+
+  virtual void OnTimerFired(uint32 timer_id);
+
+  // Fade In/Out control depending on visible flag over the time of time_ms.
+  virtual void Fade(bool visible, uint32 time_ms);
+
+  virtual void OnFadeInComplete() {}
+  virtual void OnFadeOutComplete() {}
+
+ private:
+  int alpha_shift_;
+  uint32 timer_id_;
+};
+
+}  // namespace chrome_pdf
+
+#endif  // PDF_FADING_CONTROL_H_