Site Settings Desktop: Fix issues with entering URL patterns.

BUG=633682, 614277
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:closure_compilation

Review-Url: https://codereview.chromium.org/2309283002
Cr-Commit-Position: refs/heads/master@{#417254}

chrome/browser/resources/settings/site_settings/add_site_dialog.js

@@ -43,8 +43,7 @@ Polymer({
    * @private
    */
   validate_: function() {
-    var pattern = this.addPatternWildcard(this.site_);
-    this.browserProxy.isPatternValid(pattern).then(function(isValid) {
+    this.browserProxy.isPatternValid(this.site_).then(function(isValid) {
       this.$.add.disabled = !isValid;
     }.bind(this));
   },

chrome/browser/resources/settings/site_settings/site_settings_behavior.js

@@ -359,12 +359,14 @@ var SiteSettingsBehaviorImpl = {
   },
 
   /**
-   * Adds the wildcard prefix to a pattern string.
+   * Adds the wildcard prefix to a pattern string (if missing).
    * @param {string} pattern The pattern to add the wildcard to.
    * @return {string} The resulting pattern.
    * @private
    */
   addPatternWildcard: function(pattern) {
+    if (pattern.indexOf('[*.]') > -1)
+      return pattern;
     if (pattern.startsWith('http://'))
       return pattern.replace('http://', 'http://[*.]');
     else if (pattern.startsWith('https://'))