Rewrite implementation of ClipboardRecentContent in Objective C.

components/open_from_clipboard/clipboard_recent_content_ios_impl.h

+// Copyright 2017 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 COMPONENTS_OPEN_FROM_CLIPBOARD_CLIPBOARD_RECENT_CONTENT_IOS_IMPL_H_
+#define COMPONENTS_OPEN_FROM_CLIPBOARD_CLIPBOARD_RECENT_CONTENT_IOS_IMPL_H_
+
+#import <Foundation/Foundation.h>
+
+#include "base/macros.h"
+
+// A protocol implemented by delegates to handle logging metrics.
+@protocol ClipboardRecentContentMetricsDelegate<NSObject>
+
+- (void)onClipboardChanged;
+
+@end
+
+// Objective C iOS implementation of ClipboardRecentContent.
+@interface ClipboardRecentContentIOSImpl : NSObject
+
+// |delegate| is used for metrics logging and can be nil. |authorizedSchemes|
+// should contain all schemes considered valid. |groupUserDefaults| is the
+// NSUserDefaults used to store information on pasteboard entry expiration. This
+// information will be shared with other applications in the application group.
+- (instancetype)initWithDelegate:
+                    (id<ClipboardRecentContentMetricsDelegate>)delegate
+               authorizedSchemes:(NSArray*)authorizedSchemes
+                    userDefaults:(NSUserDefaults*)groupUserDefaults
+    NS_DESIGNATED_INITIALIZER;
+
+- (instancetype)init NS_UNAVAILABLE;
+
+// ClipboardRecentContent implementation.
+- (NSURL*)getRecentURLFromClipboard;
+- (NSTimeInterval)getClipboardContentAge;
+- (void)suppressClipboardContent;
+
+// Methods below are exposed for testing purposes.

[jif, 2017/03/29 14:17:56]

I don't they they are used by tests.

[lody, 2017/03/30 13:36:34]

Line 83 in clipboard_recent_content_ios_unittest: 

  void SetStoredPasteboardChangeDate(NSDate* changeDate) {
    clipboard_content_->SetLastPasteboardChangeDate(changeDate);
    clipboard_content_->SaveToUserDefaults();
  }

[jif, 2017/03/31 13:14:47]

What I'm trying to say is that those 2 obj-c methods would need to be publicly
exposed even if there were no tests.
In other words, you can remove the comment.

[lody, 2017/03/31 13:28:19]

As clarified offline, they are in fact only needed publicly for tests.

+
+// Estimation of the date when the pasteboard changed.
+@property(nonatomic, strong) NSDate* lastPasteboardChangeDate;
+
+// Saves information to the user defaults about the latest pasteboard entry.
+- (void)saveToUserDefaults;
+// Returns the uptime. Override in tests to return custom value.

[jif, 2017/03/29 14:17:55]

Not overridden by tests. And are unittests passing?

[lody, 2017/03/30 13:36:34]

You were right. Changed so uptime is actually overriden. They are (and were)
passing.

[jif, 2017/03/31 13:14:47]

Acknowledged.

+- (NSTimeInterval)uptime;
+
+@end
+
+#endif  // COMPONENTS_OPEN_FROM_CLIPBOARD_CLIPBOARD_RECENT_CONTENT_IOS_IMPL_H_