Fix for b/2164520: Download manager should handle video/m4v MIME type.

The fix relaxes our processing of the content-disposition header by allowing unquoted filenames, and adds the m4v type to the MIME type map incase the content-disposition header was not specified.

Change-Id: Iaab0c5b17991a2c05eff5db01babe084444fd3b7

core/java/android/webkit/MimeTypeMap.java

@@ -483,6 +483,7 @@ public class MimeTypeMap {
             sMimeTypeMap.loadEntry("video/dv", "dif");
             sMimeTypeMap.loadEntry("video/dv", "dv");
             sMimeTypeMap.loadEntry("video/fli", "fli");
+            sMimeTypeMap.loadEntry("video/m4v", "m4v");
             sMimeTypeMap.loadEntry("video/mpeg", "mpeg");
             sMimeTypeMap.loadEntry("video/mpeg", "mpg");
             sMimeTypeMap.loadEntry("video/mpeg", "mpe");

core/java/android/webkit/URLUtil.java

@@ -367,19 +367,23 @@ public final class URLUtil {
 
     /** Regex used to parse content-disposition headers */
     private static final Pattern CONTENT_DISPOSITION_PATTERN =
-            Pattern.compile("attachment;\\s*filename\\s*=\\s*\"([^\"]*)\"");
+            Pattern.compile("attachment;\\s*filename\\s*=\\s*(\"?)([^\"]*)\\1\\s*$",
+            Pattern.CASE_INSENSITIVE);
 
     /*
      * Parse the Content-Disposition HTTP Header. The format of the header
      * is defined here: http://www.w3.org/Protocols/rfc2616/rfc2616-sec19.html
      * This header provides a filename for content that is going to be
      * downloaded to the file system. We only support the attachment type.
+     * Note that RFC 2616 specifies the filename value must be double-quoted.
+     * Unfortunately some servers do not quote the value so to maintain
+     * consistent behaviour with other browsers, we allow unquoted values too.
      */
     static String parseContentDisposition(String contentDisposition) {
         try {
             Matcher m = CONTENT_DISPOSITION_PATTERN.matcher(contentDisposition);
             if (m.find()) {
-                return m.group(1);
+                return m.group(2);
             }
         } catch (IllegalStateException ex) {
              // This function is defined as returning null when it can't parse the header