Make DETECT_IMPORTANT_CONTENT the default Plugins content setting based

chrome/browser/resources/options/content_settings.js

Index: chrome/browser/resources/options/content_settings.js
diff --git a/chrome/browser/resources/options/content_settings.js b/chrome/browser/resources/options/content_settings.js
index b9aed82ec306899bb4237c77b079b5deb7132bc1..db6fbf6b92829cbaa50a485efdde8a65ac8e1fb6 100644
--- a/chrome/browser/resources/options/content_settings.js
+++ b/chrome/browser/resources/options/content_settings.js
@@ -42,7 +42,6 @@ cr.define('options', function() {
    */
   function ContentSettings() {
     this.activeNavTab = null;
-    this.pluginsAllowOptionDisabled = false;
     Page.call(this, 'content',
               loadTimeData.getString('contentSettingsPageTabTitle'),
               'content-settings-page');
@@ -171,10 +170,6 @@ cr.define('options', function() {
         indicators[i].handlePrefChange(event);
       }
     }
-
-    if (this.pluginsAllowOptionDisabled) {
-      $('plugins-allow-radio').disabled = true;
-    }
   };
 
   /**
@@ -298,14 +293,6 @@ cr.define('options', function() {
   };
 
   /**
-   * Disable the 'allow' option in the Plugins section.
-   */
-  ContentSettings.disablePluginsAllowOption = function() {
-    this.pluginsAllowOptionDisabled = true;
-    $('plugins-allow-radio').disabled = true;
-  };
-
-  /**
    * Updates the microphone/camera devices menu with the given entries.
    * @param {string} type The device type.
    * @param {Array} devices List of available devices.