Remove the allow-displaying-mixed-content setting from Blink.

components/test_runner/mock_content_settings_client.h

 // Copyright 2014 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.
 
 #ifndef COMPONENTS_TEST_RUNNER_MOCK_CONTENT_SETTINGS_CLIENT_H_
 #define COMPONENTS_TEST_RUNNER_MOCK_CONTENT_SETTINGS_CLIENT_H_
 
 #include "base/macros.h"
 #include "third_party/WebKit/public/web/WebContentSettingsClient.h"
 
@@ skipping 11 matching lines @@
   ~MockContentSettingsClient() override;
 
   // blink::WebContentSettingsClient:
   bool allowImage(bool enabled_per_settings,
                   const blink::WebURL& image_url) override;
   bool allowScript(bool enabled_per_settings) override;
   bool allowScriptFromSource(bool enabled_per_settings,
                              const blink::WebURL& script_url) override;
   bool allowStorage(bool local) override;
   bool allowPlugins(bool enabled_per_settings) override;
-  bool allowDisplayingInsecureContent(bool enabled_per_settings,
-                                      const blink::WebURL& url) override;
   bool allowRunningInsecureContent(bool enabled_per_settings,
                                    const blink::WebSecurityOrigin& context,
                                    const blink::WebURL& url) override;
   bool allowAutoplay(bool default_value) override;
 
   void SetDelegate(WebTestDelegate* delegate);
 
  private:
   WebTestDelegate* delegate_;
 
   LayoutTestRuntimeFlags* flags_;
 
   DISALLOW_COPY_AND_ASSIGN(MockContentSettingsClient);
 };
 
 }  // namespace test_runner
 
 #endif  // COMPONENTS_TEST_RUNNER_MOCK_CONTENT_SETTINGS_CLIENT_H_