Reland of Improve linearized pdf load/show time.

pdf/timer.h

Index: pdf/timer.h
diff --git a/pdf/timer.h b/pdf/timer.h
new file mode 100644
index 0000000000000000000000000000000000000000..a27f78f3d0b9850e88af8a3baa8cbff3cb72c5ff
--- /dev/null
+++ b/pdf/timer.h
@@ -0,0 +1,35 @@
+// Copyright 2016 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_TIMER_H_
+#define PDF_TIMER_H_
+
+#include "base/macros.h"
+#include "ppapi/utility/completion_callback_factory.h"
+
+namespace chrome_pdf {
+
+// Timer implementation for pepper plugins, based on pp::Core::CallOnMainThread.
+// We can not use base::Timer for plugins, because they have no
+// base::MessageLoop, on which it is based.
+class Timer {
+ public:
+  explicit Timer(int delay_in_milliseconds);
+  virtual ~Timer();
+
+  virtual void OnTimer() = 0;
+
+ private:
+  void PostCallback();
+  void TimerProc(int32_t result);
+
+  int delay_;
+  pp::CompletionCallbackFactory<Timer> callback_factory_;
+
+  DISALLOW_COPY_AND_ASSIGN(Timer);
+};
+
+}  // namespace chrome_pdf
+
+#endif  // PDF_TIMER_H_