Fix detection of clipboard change after device restart.

components/open_from_clipboard/clipboard_recent_content_ios.mm

 // Copyright 2015 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.
 
 #include "components/open_from_clipboard/clipboard_recent_content_ios.h"
 
 #import <UIKit/UIKit.h>
 
 #include "base/logging.h"
 #include "base/macros.h"
 #include "base/memory/singleton.h"
 #include "base/metrics/user_metrics.h"
 #include "base/strings/sys_string_conversions.h"
+#include "base/sys_info.h"
 #include "url/gurl.h"
 #include "url/url_constants.h"
 
 ClipboardRecentContent* ClipboardRecentContent::GetInstance() {
   return ClipboardRecentContentIOS::GetInstance();
 }
 
 // Bridge that forwards pasteboard change notifications to its delegate.
 @interface PasteboardNotificationListenerBridge : NSObject {
   ClipboardRecentContentIOS* _delegate;
@@ skipping 85 matching lines @@
     lastPasteboardChangeDate_.reset([[NSDate date] retain]);
     lastPasteboardChangeCount_ = [UIPasteboard generalPasteboard].changeCount;
     SaveToUserDefaults();
   }
 }
 
 ClipboardRecentContentIOS::ClipboardRecentContentIOS()
     : ClipboardRecentContent() {
   urlFromPasteboardCache_ = URLFromPasteboard();
   LoadFromUserDefaults();
-  if ([UIPasteboard generalPasteboard].changeCount !=
-      lastPasteboardChangeCount_) {
-    PasteboardChanged();
+  // The pasteboard's changeCount is reset to zero when the device is restarted.
+  // This means that even if |changeCount| hasn't changed, the pasteboard
+  // content could have changed. In order to avoid missing pasteboard changes,
+  // the changeCount is reset if the device has restarted.
+  NSInteger changeCount = [UIPasteboard generalPasteboard].changeCount;
+  if (changeCount != lastPasteboardChangeCount_ ||
+      DeviceRestartedSincePasteboardChanged()) {
+     PasteboardChanged();
   }
   notificationBridge_.reset(
       [[PasteboardNotificationListenerBridge alloc] initWithDelegate:this]);
 }
 
 ClipboardRecentContentIOS::~ClipboardRecentContentIOS() {
 }
 
 GURL ClipboardRecentContentIOS::URLFromPasteboard() {
   const std::string clipboard =
@@ skipping 21 matching lines @@
   DCHECK(!lastPasteboardChangeDate_ ||
          [lastPasteboardChangeDate_ isKindOfClass:[NSDate class]]);
 }
 
 void ClipboardRecentContentIOS::SaveToUserDefaults() {
   [[NSUserDefaults standardUserDefaults] setInteger:lastPasteboardChangeCount_
                                              forKey:kPasteboardChangeCountKey];
   [[NSUserDefaults standardUserDefaults] setObject:lastPasteboardChangeDate_
                                             forKey:kPasteboardChangeDateKey];
 }
+
+bool ClipboardRecentContentIOS::DeviceRestartedSincePasteboardChanged() {
+  int64 secondsSincePasteboardChange =
+      -static_cast<int64>([lastPasteboardChangeDate_ timeIntervalSinceNow]);
+  int64 secondsSinceLastDeviceRestart = base::SysInfo::Uptime() / 1000;
+  return secondsSincePasteboardChange > secondsSinceLastDeviceRestart;
+}