Fixed "blocking io" from FixupPath on UI thread.

net/base/filename_util.cc

Index: net/base/filename_util.cc
diff --git a/net/base/filename_util.cc b/net/base/filename_util.cc
index c9d5fe4b5f2652bb7ab47c57d3cf80fe7ab95b9e..7d60c39683d5eddae48cbf312d582cf89aafb045 100644
--- a/net/base/filename_util.cc
+++ b/net/base/filename_util.cc
@@ -63,6 +63,39 @@ GURL FilePathToFileURL(const base::FilePath& path) {
   return GURL(url_string);
 }
 
+GURL FilePathToFileURLNoCWD(const base::FilePath& path) {
+  // Produce a URL like "file:///C:/foo" for a regular file, or
+  // "file://///server/path" for UNC. The URL canonicalizer will fix up the
+  // latter case to be the canonical UNC form: "file://server/path"
+  base::FilePath::StringType url_string(kFileURLPrefix);
+  url_string.append(path.value());
+  // Do replacement of some characters. Since we assume the input is a
+  // literal filename, anything the URL parser might consider special should
+  // be escaped here.
+
+  // must be the first substitution since others will introduce percents as the
+  // escape character
+  ReplaceSubstringsAfterOffset(&url_string, 0, FILE_PATH_LITERAL("%"),
+                               FILE_PATH_LITERAL("%25"));
+
+  // semicolon is supposed to be some kind of separator according to RFC 2396
+  ReplaceSubstringsAfterOffset(&url_string, 0, FILE_PATH_LITERAL(";"),
+                               FILE_PATH_LITERAL("%3B"));
+
+  ReplaceSubstringsAfterOffset(&url_string, 0, FILE_PATH_LITERAL("#"),
+                               FILE_PATH_LITERAL("%23"));
+
+  ReplaceSubstringsAfterOffset(&url_string, 0, FILE_PATH_LITERAL("?"),
+                               FILE_PATH_LITERAL("%3F"));
+
+#if defined(OS_POSIX)
+  ReplaceSubstringsAfterOffset(&url_string, 0, FILE_PATH_LITERAL("\\"),
+                               FILE_PATH_LITERAL("%5C"));
+#endif

[davidben, 2015/04/14 16:26:22]

This is too much code to be duplicated. Move things to a helper function.

+
+  return GURL(url_string);
+}
+
 bool FileURLToFilePath(const GURL& url, base::FilePath* file_path) {
   *file_path = base::FilePath();
   base::FilePath::StringType& file_path_str =