Reverts a temporary fix for UIPasteboard on iOS 9 beta 5.

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.
 
 #import "components/open_from_clipboard/clipboard_recent_content_ios.h"
 
 #import <CommonCrypto/CommonDigest.h>
 #include <stddef.h>
 #include <stdint.h>
 #import <UIKit/UIKit.h>
@@ skipping 130 matching lines @@
 
 void ClipboardRecentContentIOS::SuppressClipboardContent() {
   // User cleared the user data. The pasteboard entry must be removed from the
   // omnibox list. Force entry expiration by setting copy date to 1970.
   last_pasteboard_change_date_.reset(
       [[NSDate alloc] initWithTimeIntervalSince1970:0]);
   SaveToUserDefaults();
 }
 
 void ClipboardRecentContentIOS::PasteboardChanged() {
-  NSString* pasteboard_string = [[UIPasteboard generalPasteboard] string];
-  if (!pasteboard_string)
-    return;
   url_from_pasteboard_cache_ = URLFromPasteboard();
   if (!url_from_pasteboard_cache_.is_empty()) {
     base::RecordAction(
         base::UserMetricsAction("MobileOmniboxClipboardChanged"));
   }
   last_pasteboard_change_date_.reset([[NSDate date] retain]);
   last_pasteboard_change_count_ = [UIPasteboard generalPasteboard].changeCount;
+  NSString* pasteboard_string = [[UIPasteboard generalPasteboard] string];
+  if (!pasteboard_string) {
+    pasteboard_string = @"";
+  }
   NSData* MD5 = WeakMD5FromNSString(pasteboard_string);
   last_pasteboard_entry_md5_.reset([MD5 retain]);
   SaveToUserDefaults();
 }
 
 ClipboardRecentContentIOS::ClipboardRecentContentIOS(
     const std::string& application_scheme,
     NSUserDefaults* group_user_defaults)
     : application_scheme_(application_scheme),
       shared_user_defaults_([group_user_defaults retain]) {
   Init(base::SysInfo::Uptime());
 }
 
 ClipboardRecentContentIOS::ClipboardRecentContentIOS(
     const std::string& application_scheme,
     base::TimeDelta uptime)
     : application_scheme_(application_scheme),
       shared_user_defaults_([[NSUserDefaults standardUserDefaults] retain]) {
   Init(uptime);
 }
 
 bool ClipboardRecentContentIOS::HasPasteboardChanged(base::TimeDelta uptime) {
-  // If [[UIPasteboard generalPasteboard] string] is nil, the content of the
-  // pasteboard cannot be accessed. This case should not be considered as a
-  // pasteboard change.
-  NSString* pasteboard_string = [[UIPasteboard generalPasteboard] string];
-  if (!pasteboard_string)
-    return NO;
-
   // If |MD5Changed|, we know for sure there has been at least one pasteboard
   // copy since last time it was checked.
   // If the pasteboard content is still the same but the device was not
   // rebooted, the change count can be checked to see if it changed.
   // Note: due to a mismatch between the actual behavior and documentation, and
   // lack of consistency on different reboot scenarios, the change count cannot
   // be checked after a reboot.
   // See radar://21833556 for more information.
   NSInteger change_count = [UIPasteboard generalPasteboard].changeCount;
   bool change_count_changed = change_count != last_pasteboard_change_count_;
 
   bool not_rebooted = uptime > GetClipboardContentAge();
   if (not_rebooted)
     return change_count_changed;
 
+  NSString* pasteboard_string = [[UIPasteboard generalPasteboard] string];
+  if (!pasteboard_string) {
+    pasteboard_string = @"";
+  }
   NSData* md5 = WeakMD5FromNSString(pasteboard_string);
   BOOL md5_changed = ![md5 isEqualToData:last_pasteboard_entry_md5_];
 
   return md5_changed;
 }
 
 void ClipboardRecentContentIOS::Init(base::TimeDelta uptime) {
   last_pasteboard_change_count_ = NSIntegerMax;
   url_from_pasteboard_cache_ = URLFromPasteboard();
   LoadFromUserDefaults();
@@ skipping 59 matching lines @@
 void ClipboardRecentContentIOS::SaveToUserDefaults() {
   [shared_user_defaults_ setInteger:last_pasteboard_change_count_
                              forKey:kPasteboardChangeCountKey];
   [shared_user_defaults_ setObject:last_pasteboard_change_date_
                             forKey:kPasteboardChangeDateKey];
   [shared_user_defaults_ setObject:last_pasteboard_entry_md5_
                             forKey:kPasteboardEntryMD5Key];
   [shared_user_defaults_ setObject:last_displayed_pasteboard_entry_
                             forKey:kLastDisplayedPasteboardEntryKey];
 }