Refactor ClipboardRecentContent singleton creation.

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 "components/open_from_clipboard/clipboard_recent_content_ios.h"
 
 #import <UIKit/UIKit.h>
 
-#include "base/ios/ios_util.h"
+#import "base/ios/ios_util.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
+
+// Initialize the PasteboardNotificationListenerBridge with |delegate| which
+// must not be null.
+- (instancetype)initWithDelegate:(ClipboardRecentContentIOS*)delegate
+    NS_DESIGNATED_INITIALIZER;
+
+- (instancetype)init NS_UNAVAILABLE;
+
+@end
+
+@implementation PasteboardNotificationListenerBridge {
+  ClipboardRecentContentIOS* _delegate;
 }
 
-// Bridge that forwards pasteboard change notifications to its delegate.
-@interface PasteboardNotificationListenerBridge : NSObject {
-  ClipboardRecentContentIOS* _delegate;
+- (instancetype)init {
+  NOTREACHED();
+  return nil;
 }
-@end
 
-@implementation PasteboardNotificationListenerBridge
-
-- (id)initWithDelegate:(ClipboardRecentContentIOS*)delegate {
+- (instancetype)initWithDelegate:(ClipboardRecentContentIOS*)delegate {
   DCHECK(delegate);
   self = [super init];
   if (self) {
     _delegate = delegate;
     [[NSNotificationCenter defaultCenter]
         addObserver:self
            selector:@selector(pasteboardChangedNotification:)
                name:UIPasteboardChangedNotification
              object:[UIPasteboard generalPasteboard]];
     [[NSNotificationCenter defaultCenter]
@@ skipping 35 matching lines @@
 base::TimeDelta kMaximumAgeOfClipboard = base::TimeDelta::FromHours(3);
 // Schemes accepted by the ClipboardRecentContentIOS.
 const char* kAuthorizedSchemes[] = {
     url::kHttpScheme,
     url::kHttpsScheme,
     url::kDataScheme,
     url::kAboutScheme,
 };
 }  // namespace
 
-ClipboardRecentContentIOS* ClipboardRecentContentIOS::GetInstance() {
-  return Singleton<ClipboardRecentContentIOS>::get();
-}
-
 bool ClipboardRecentContentIOS::GetRecentURLFromClipboard(GURL* url) const {
   DCHECK(url);
   if (GetClipboardContentAge() > kMaximumAgeOfClipboard ||
       [UIPasteboard generalPasteboard].changeCount ==
           suppressedPasteboardEntryCount_) {
     return false;
   }
 
   if (urlFromPasteboardCache_.is_valid()) {
     *url = urlFromPasteboardCache_;
@@ skipping 19 matching lines @@
     base::RecordAction(
         base::UserMetricsAction("MobileOmniboxClipboardChanged"));
   }
   lastPasteboardChangeDate_.reset([[NSDate date] retain]);
   lastPasteboardChangeCount_ = [UIPasteboard generalPasteboard].changeCount;
   if (lastPasteboardChangeCount_ != suppressedPasteboardEntryCount_) {
     suppressedPasteboardEntryCount_ = NSIntegerMax;
   }
 }
 
-ClipboardRecentContentIOS::ClipboardRecentContentIOS() {
+ClipboardRecentContentIOS::ClipboardRecentContentIOS(
+    const std::string& application_scheme)
+    : application_scheme_(application_scheme) {
   Init(base::TimeDelta::FromMilliseconds(base::SysInfo::Uptime()));
 }
 
-ClipboardRecentContentIOS::ClipboardRecentContentIOS(base::TimeDelta uptime) {
+ClipboardRecentContentIOS::ClipboardRecentContentIOS(
+    const std::string& application_scheme,
+    base::TimeDelta uptime)
+    : application_scheme_(application_scheme) {
   Init(uptime);
 }
 
 void ClipboardRecentContentIOS::Init(base::TimeDelta uptime) {
   lastPasteboardChangeCount_ = NSIntegerMax;
   suppressedPasteboardEntryCount_ = NSIntegerMax;
   urlFromPasteboardCache_ = URLFromPasteboard();
   LoadFromUserDefaults();
 
   // On iOS 7 (unlike on iOS 8, despite what the documentation says), the change
@@ skipping 72 matching lines @@
 
 void ClipboardRecentContentIOS::SaveToUserDefaults() {
   NSUserDefaults* defaults = [NSUserDefaults standardUserDefaults];
   [defaults setInteger:lastPasteboardChangeCount_
                 forKey:kPasteboardChangeCountKey];
   [defaults setObject:lastPasteboardChangeDate_
                forKey:kPasteboardChangeDateKey];
   [defaults setInteger:suppressedPasteboardEntryCount_
                 forKey:kSuppressedPasteboardEntryCountKey];
 }