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

chrome/renderer/content_settings_observer.cc

Index: chrome/renderer/content_settings_observer.cc
diff --git a/chrome/renderer/content_settings_observer.cc b/chrome/renderer/content_settings_observer.cc
index 5e4e27c9667fc09d0aa5b25b156bb38f59faaeda..c5a678bf5a1b438b470acbdfaad380bb564c4190 100644
--- a/chrome/renderer/content_settings_observer.cc
+++ b/chrome/renderer/content_settings_observer.cc
@@ -391,15 +391,6 @@ bool ContentSettingsObserver::allowMutationEvents(bool default_value) {
   return IsPlatformApp() ? false : default_value;
 }
 
-bool ContentSettingsObserver::allowDisplayingInsecureContent(
-    bool allowed_per_settings,
-    const blink::WebURL& resource_url) {
-  DCHECK(allowed_per_settings);
-  ReportInsecureContent(SslInsecureContentType::DISPLAY);
-  FilteredReportInsecureContentDisplayed(GURL(resource_url));
-  return true;
-}
-
 bool ContentSettingsObserver::allowRunningInsecureContent(
     bool allowed_per_settings,
     const blink::WebSecurityOrigin& origin,
@@ -426,6 +417,12 @@ bool ContentSettingsObserver::allowAutoplay(bool default_value) {
          CONTENT_SETTING_ALLOW;
 }
 
+void ContentSettingsObserver::passiveInsecureContentFound(
+    const blink::WebURL& resource_url) {
+  ReportInsecureContent(SslInsecureContentType::DISPLAY);
+  FilteredReportInsecureContentDisplayed(GURL(resource_url));
+}
+
 void ContentSettingsObserver::didUseKeygen() {
   WebFrame* frame = render_frame()->GetWebFrame();
   Send(new ChromeViewHostMsg_DidUseKeygen(