Download filename encoding fix [try2]:

net/base/net_util.cc

Index: net/base/net_util.cc
diff --git a/net/base/net_util.cc b/net/base/net_util.cc
index 60f626d44cec4bbd9c223475485c35f912923523..5eb2e68f4648f417f186d56503643bba7c2eccb8 100644
--- a/net/base/net_util.cc
+++ b/net/base/net_util.cc
@@ -272,6 +272,11 @@ bool DecodeWord(const std::string& encoded_word,
                 const std::string& referrer_charset,
                 bool* is_rfc2047,
                 std::string* output) {
+  *is_rfc2047 = false;
+  output->clear();
+  if (encoded_word.empty())
+    return true;
+
   if (!IsStringASCII(encoded_word)) {
     // Try UTF-8, referrer_charset and the native OS default charset in turn.
     if (IsStringUTF8(encoded_word)) {
@@ -287,7 +292,7 @@ bool DecodeWord(const std::string& encoded_word,
         *output = WideToUTF8(base::SysNativeMBToWide(encoded_word));
       }
     }
-    *is_rfc2047 = false;
+
     return true;
   }
 
@@ -1081,7 +1086,7 @@ FilePath GetSuggestedFilename(const GURL& url,
   }
 
   const std::string filename_from_cd = GetFileNameFromCD(content_disposition,
-                                                          referrer_charset);
+                                                         referrer_charset);
 #if defined(OS_WIN)
   FilePath::StringType filename = UTF8ToWide(filename_from_cd);
 #elif defined(OS_POSIX)
@@ -1102,10 +1107,21 @@ FilePath GetSuggestedFilename(const GURL& url,
       const std::string unescaped_url_filename = UnescapeURLComponent(
           url.ExtractFileName(),
           UnescapeRule::SPACES | UnescapeRule::URL_SPECIAL_CHARS);
+
+      // The URL's path should be escaped UTF-8, but may not be.
+      std::string decoded_filename = unescaped_url_filename;
+      if (!IsStringASCII(decoded_filename)) {
+        bool ignore;
+        // TODO(jshin): this is probably not robust enough. To be sure, we
+        // need encoding detection.
+        DecodeWord(unescaped_url_filename, referrer_charset, &ignore,
+                   &decoded_filename);
+      }
+
 #if defined(OS_WIN)
-      filename = UTF8ToWide(unescaped_url_filename);
+      filename = UTF8ToWide(decoded_filename);
 #elif defined(OS_POSIX)
-      filename = unescaped_url_filename;
+      filename = decoded_filename;
 #endif
     }
   }