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

content/public/browser/web_contents_delegate.cc

Index: content/public/browser/web_contents_delegate.cc
diff --git a/content/public/browser/web_contents_delegate.cc b/content/public/browser/web_contents_delegate.cc
index 01c9c0897ea087977474a91e4ce3c0f758710243..79c37b37447ec0165846e201de1103a757f6db47 100644
--- a/content/public/browser/web_contents_delegate.cc
+++ b/content/public/browser/web_contents_delegate.cc
@@ -272,4 +272,12 @@ void WebContentsDelegate::RequestAppBannerFromDevTools(
     content::WebContents* web_contents) {
 }
 
+bool WebContentsDelegate::ShouldAllowRunningInsecureContent(
+    bool allowed_per_settings,
+    const url::Origin& origin,
+    const GURL& resource_url,
+    WebContents* web_contents) {
+  return allowed_per_settings;
+}
+
 }  // namespace content