PlzNavigate: Move navigation-level mixed content checks to the browser.

content/browser/frame_host/render_frame_host_delegate.cc

 // Copyright 2013 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 <stddef.h>
 
 #include "base/callback.h"
 #include "base/strings/string16.h"
 #include "build/build_config.h"
 #include "content/browser/frame_host/render_frame_host_delegate.h"
@@ skipping 75 matching lines @@
     RenderFrameHost* target_rfh,
     SiteInstance* source_site_instance) const {
   return false;
 }
 
 std::unique_ptr<WebUIImpl>
 RenderFrameHostDelegate::CreateWebUIForRenderFrameHost(const GURL& url) {
   return nullptr;
 }
 
+bool RenderFrameHostDelegate::ShouldAllowRunningInsecureContent(
+    bool allowed_per_settings,
+    const url::Origin& origin,
+    const GURL& resource_url,
+    WebContents* web_contents) {
+  return false;

[jam, 2017/01/12 01:39:00]

nit: why not return allowed_per_settings?

[carlosk, 2017/01/12 17:44:02]

My reasoning was:
B) These methods were not required from them before anyway, so there's no
current users (beyond the "right" one).
A) For the 2 existing sub-classes of RenderFrameHostDelegate beyond
WebContentsImpl, calling any mixed content method on them looks like an error.

I even considered using NOTREACHED. IIUC these are default implemented only to
avoid the need for subclasses to create an empty override and not because they
are expected to be called.

WDYT?

[jam, 2017/01/12 18:24:07]

seems fair, we better not have this error in our interstitials :)

+}
+
 }  // namespace content