Check for blacklist wildcards before creating GURL

The policy blacklist parser used to first check for "file" schemes first as a
special case before checking for wildcard hosts like "http://*", and the file
special-case had it's own wildcard special casing.

I am working on making "*" an invalid host character, and with this future
patch, creating a GURL of "file://*" will fail. This change moves the wildcard
handling above the file scheme checking so it will work regardless of whether
"*" is a valid host character or not.

The particular structure of this code looks like a result of adding the
wildcard handling ( https://codereview.chromium.org/1692503002/ ) after the
file handling was already in place.

BUG=652808

Review-Url: https://chromiumcodereview.appspot.com/2426733002
Cr-Commit-Position: refs/heads/master@{#426532}

components/policy/core/browser/url_blacklist_manager.cc

@@ -262,6 +262,19 @@ bool URLBlacklist::FilterToComponents(const std::string& filter,
   const std::string lc_filter = base::ToLowerASCII(filter);
   const std::string url_scheme = url_formatter::SegmentURL(filter, &parsed);
 
+  // Check if it's a scheme wildcard pattern. We support both versions
+  // (scheme:* and scheme://*) the later being consistent with old filter
+  // definitions.
+  if (lc_filter == url_scheme + ":*" || lc_filter == url_scheme + "://*") {
+    scheme->assign(url_scheme);
+    host->clear();
+    *match_subdomains = true;
+    *port = 0;
+    path->clear();
+    query->clear();
+    return true;
+  }
+
   if (url_scheme == url::kFileScheme) {
     base::FilePath file_path;
     if (!net::FileURLToFilePath(GURL(filter), &file_path))
@@ -271,11 +284,7 @@ bool URLBlacklist::FilterToComponents(const std::string& filter,
     host->clear();
     *match_subdomains = true;
     *port = 0;
-    // Special path when the |filter| is 'file://*' or 'file:*'.
-    if (lc_filter == "file:*" || lc_filter == "file://*")
-      path->clear();
-    else
-      *path = file_path.AsUTF8Unsafe();
+    *path = file_path.AsUTF8Unsafe();
 #if defined(FILE_PATH_USES_WIN_SEPARATORS)
     // Separators have to be canonicalized on Windows.
     std::replace(path->begin(), path->end(), '\\', '/');
@@ -284,19 +293,6 @@ bool URLBlacklist::FilterToComponents(const std::string& filter,
     return true;
   }
 
-  // Check if it's a scheme wildcard pattern. We support both versions
-  // (scheme:* and scheme://*) the later being consistent with old filter
-  // definitions.
-  if (lc_filter == url_scheme + ":*" || lc_filter == url_scheme + "://*") {
-    scheme->assign(url_scheme);
-    host->clear();
-    *match_subdomains = true;
-    *port = 0;
-    path->clear();
-    query->clear();
-    return true;
-  }
-
   // According to documentation host can't be empty.
   if (!parsed.host.is_nonempty())
     return false;