Make Android Clipboard Keep Track of Last Modified Time

ui/base/clipboard/clipboard_android.cc

Index: ui/base/clipboard/clipboard_android.cc
diff --git a/ui/base/clipboard/clipboard_android.cc b/ui/base/clipboard/clipboard_android.cc
index 2da7c540e6400e921e510b3668ad2c79ea8162b3..8f35282acde0eb701fedebef5ec6aaaad0e84243 100644
--- a/ui/base/clipboard/clipboard_android.cc
+++ b/ui/base/clipboard/clipboard_android.cc
@@ -4,6 +4,9 @@
 
 #include "ui/base/clipboard/clipboard_android.h"
 
+#include <algorithm>
+
+#include "base/android/context_utils.h"
 #include "base/android/jni_string.h"
 #include "base/lazy_instance.h"
 #include "base/stl_util.h"
@@ -47,6 +50,7 @@ class ClipboardMap {
  public:
   ClipboardMap();
   std::string Get(const std::string& format);
+  int64_t GetLastClipboardChangeTimeInMillis();
   bool HasFormat(const std::string& format);
   void Set(const std::string& format, const std::string& data);
   void CommitToAndroidClipboard();
@@ -57,6 +61,8 @@ class ClipboardMap {
   std::map<std::string, std::string> map_;
   base::Lock lock_;
 
+  int64_t last_clipboard_change_time_ms_;
+
   // Java class and methods for the Android ClipboardManager.
   ScopedJavaGlobalRef<jobject> clipboard_manager_;
 };
@@ -74,6 +80,12 @@ std::string ClipboardMap::Get(const std::string& format) {
   return it == map_.end() ? std::string() : it->second;
 }
 
+int64_t ClipboardMap::GetLastClipboardChangeTimeInMillis() {
+  base::AutoLock lock(lock_);
+  UpdateFromAndroidClipboard();
+  return last_clipboard_change_time_ms_;
+}
+
 bool ClipboardMap::HasFormat(const std::string& format) {
   base::AutoLock lock(lock_);
   UpdateFromAndroidClipboard();
@@ -158,6 +170,9 @@ void ClipboardMap::UpdateFromAndroidClipboard() {
 
   AddMapEntry(env, &android_clipboard_state, kPlainTextFormat, jtext);
   AddMapEntry(env, &android_clipboard_state, kHTMLFormat, jhtml);
+  last_clipboard_change_time_ms_ =
+      Java_Clipboard_getClipboardContentChangeTimeInMillis(env,
+                                                           clipboard_manager_);
 
   if (!MapIsSubset(android_clipboard_state, map_))
     android_clipboard_state.swap(map_);
@@ -399,6 +414,12 @@ void ClipboardAndroid::ReadData(const Clipboard::FormatType& format,
   *result = g_map.Get().Get(format.ToString());
 }
 
+base::Time ClipboardAndroid::GetClipboardLastModifiedTime() const {
+  DCHECK(CalledOnValidThread());
+  return base::Time::FromJavaTime(
+      g_map.Get().GetLastClipboardChangeTimeInMillis());
+}
+
 // Main entry point used to write several values in the clipboard.
 void ClipboardAndroid::WriteObjects(ClipboardType type,
                                     const ObjectMap& objects) {