Push one function from the Mac drag/drop util code to ui/.

ui/base/dragdrop/cocoa_dnd_util.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 "ui/base/dragdrop/cocoa_dnd_util.h"
+
+#include "base/logging.h"
+#include "base/sys_string_conversions.h"
+#include "googleurl/src/gurl.h"
+#import "third_party/mozilla/NSPasteboard+Utils.h"
+
+namespace ui {
+
+BOOL PopulateURLAndTitleFromPasteboard(GURL* url,
+                                       string16* title,
+                                       NSPasteboard* pboard,
+                                       BOOL convert_filenames) {
+  CHECK(url);
+
+  // Bail out early if there's no URL data.
+  if (![pboard containsURLData])
+    return NO;
+
+  // -getURLs:andTitles:convertingFilenames: will already validate URIs so we
+  // don't need to again. The arrays returned are both of NSStrings.
+  NSArray* url_array = nil;
+  NSArray* title_array = nil;
+  [pboard getURLs:&url_array andTitles:&title_array
+      convertingFilenames:convert_filenames];
+  DCHECK_EQ([url_array count], [title_array count]);
+  // It's possible that no URLs were actually provided!
+  if (![url_array count])
+    return NO;
+  NSString* url_string = [url_array objectAtIndex:0];
+  if ([url_string length]) {
+    // Check again just to make sure to not assign NULL into a std::string,
+    // which throws an exception.
+    const char* utf8_url = [url_string UTF8String];
+    if (utf8_url) {
+      *url = GURL(utf8_url);
+      // Extra paranoia check.
+      if (title && [title_array count])
+        *title = base::SysNSStringToUTF16([title_array objectAtIndex:0]);
+    }
+  }
+  return YES;
+}
+
+}  // namespace ui