Clipboard Android - Store and Read Last Modified Time from Prefs

ui/base/clipboard/clipboard_android.h

 // Copyright 2014 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 UI_BASE_CLIPBOARD_CLIPBOARD_ANDROID_H_
 #define UI_BASE_CLIPBOARD_CLIPBOARD_ANDROID_H_
 
 #include "ui/base/clipboard/clipboard.h"
 
 #include <jni.h>
 #include <stddef.h>
 #include <stdint.h>
 
 #include "base/android/scoped_java_ref.h"
+#include "base/callback_forward.h"
 #include "base/macros.h"
 #include "base/time/time.h"
 
 namespace ui {
 
 class ClipboardAndroid : public Clipboard {
  public:
+  // Callback called whenever the clipboard is modified.  The parameter
+  // represents the time of the modification.
+  typedef base::Callback<void(base::Time)> Modified;

[Bernhard Bauer, 2017/04/27 09:27:17]

Nit: ModifiedCallback? Or just inline the type; it's not that complicated.

[dcheng, 2017/04/27 15:25:39]

Nit 2: prefer using A = B; over typedef B A;

[Mark P, 2017/04/27 19:25:59]

Sounds good to me.  Done.
True, but it's used enough that inlining is cumbersome.  (I could at least four
places in the .cc file.)
Done.

+
   // Called by Java when the Java Clipboard is notified that the clipboard has
   // changed.
   void OnPrimaryClipChanged(JNIEnv* env,
                             const base::android::JavaParamRef<jobject>& obj);
 
+  // Sets the callback called whenever the clipboard is modified.
+  UI_BASE_EXPORT void SetModifiedCallback(Modified cb);
+
+  // Sets the last modified time without calling the above callback.
+  UI_BASE_EXPORT void SetLastModifiedTimeWithoutRunningCallback(
+      base::Time time);
+
  private:
   friend class Clipboard;
 
   ClipboardAndroid();
   ~ClipboardAndroid() override;
 
   // Clipboard overrides:
   void OnPreShutdown() override;
   uint64_t GetSequenceNumber(ClipboardType type) const override;
   bool IsFormatAvailable(const FormatType& format,
@@ skipping 37 matching lines @@
 
   DISALLOW_COPY_AND_ASSIGN(ClipboardAndroid);
 };
 
 // Registers the ClipboardAndroid native method.
 bool RegisterClipboardAndroid(JNIEnv* env);
 
 }  // namespace ui
 
 #endif  // UI_BASE_CLIPBOARD_CLIPBOARD_ANDROID_H_