content: Extract url utility functions into url_utils.{h,cc}

chrome/browser/download/download_util.h

Index: chrome/browser/download/download_util.h
diff --git a/chrome/browser/download/download_util.h b/chrome/browser/download/download_util.h
index 6494254d692c6448896993e7d07e803a0681288d..b74afbf89563961ce83be535d6bf0469d2c2cf53 100644
--- a/chrome/browser/download/download_util.h
+++ b/chrome/browser/download/download_util.h
@@ -143,9 +143,6 @@ void DragDownload(const content::DownloadItem* download,
 // Get the localized status text for an in-progress download.
 string16 GetProgressStatusText(content::DownloadItem* download);
 
-// Check whether we can do the saving page operation for the specified URL.
-bool IsSavableURL(const GURL& url);
-
 // Record the total number of items and the number of in-progress items showing
 // in the shelf when it closes.  Set |autoclose| to true when the shelf is
 // closing itself, false when the user explicitly closed it.