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

chrome/browser/ui/cocoa/find_pasteboard_unittest.mm

 // Copyright (c) 2011 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 <Cocoa/Cocoa.h>
 
 #include "base/memory/scoped_nsobject.h"
 #import "chrome/browser/ui/cocoa/cocoa_test_helper.h"
-#import "content/browser/find_pasteboard.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "testing/platform_test.h"
+#import "ui/base/clipboard/find_pasteboard.h"
 
 // A subclass of FindPasteboard that doesn't write to the real find pasteboard.
 @interface FindPasteboardTesting : FindPasteboard {
  @public
   int notificationCount_;
  @private
   NSPasteboard* pboard_;
 }
 - (NSPasteboard*)findPboard;
 
@@ skipping 84 matching lines @@
 
   [pboard_.get() setFindPboardText:@"otherer text"];
   [pboard_.get() loadTextFromPasteboard:nil];
   EXPECT_EQ(3, pboard_.get()->notificationCount_);
 
   [[NSNotificationCenter defaultCenter] removeObserver:pboard_.get()];
 }
 
 
 }  // namespace