Move FindPasteboard to ui/base/cocoa since it's used by two modules (content+chrome).

ui/base/clipboard/find_pasteboard.mm

 // Copyright (c) 2009 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 "content/browser/find_pasteboard.h"
+#import "ui/base/clipboard/find_pasteboard.h"
 
 #include "base/logging.h"
 #include "base/sys_string_conversions.h"
 
 NSString* kFindPasteboardChangedNotification =
     @"kFindPasteboardChangedNotification_Chrome";
 
 @implementation FindPasteboard
 
 + (FindPasteboard*)sharedInstance {
@@ skipping 57 matching lines @@
         postNotificationName:kFindPasteboardChangedNotification
                       object:self];
   }
 }
 
 @end
 
 string16 GetFindPboardText() {
   return base::SysNSStringToUTF16([[FindPasteboard sharedInstance] findText]);
 }