Remove InsecureContentInfobarDelegate, which has been broken for a while

content/renderer/render_view_impl.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/renderer/render_view_impl.h"
 
 #include <algorithm>
 #include <cmath>
 #include <memory>
 
@@ skipping 985 matching lines @@
   // default value if not).
   settings->setAccelerated2dCanvasMSAASampleCount(
       prefs.accelerated_2d_canvas_msaa_sample_count);
 
   settings->setUnifiedTextCheckerEnabled(prefs.unified_textchecker_enabled);
 
   // Tabs to link is not part of the settings. WebCore calls
   // ChromeClient::tabsToLinks which is part of the glue code.
   web_view->setTabsToLinks(prefs.tabs_to_links);
 
-  settings->setAllowDisplayOfInsecureContent(
-      prefs.allow_displaying_insecure_content);
   settings->setAllowRunningOfInsecureContent(
       prefs.allow_running_insecure_content);
   settings->setDisableReadingFromCanvas(prefs.disable_reading_from_canvas);
   settings->setStrictMixedContentChecking(prefs.strict_mixed_content_checking);
 
   settings->setStrictlyBlockBlockableMixedContent(
       prefs.strictly_block_blockable_mixed_content);
 
   settings->setStrictMixedContentCheckingForPlugin(
       prefs.block_mixed_plugin_content);
@@ skipping 2222 matching lines @@
         return render_frame->focused_pepper_plugin();
     }
     frame = frame->traverseNext(false);
   }
 
   return nullptr;
 }
 #endif
 
 }  // namespace content