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

third_party/WebKit/LayoutTests/http/tests/security/mixedContent/insecure-formSubmission-in-main-frame-blocked.html

Index: third_party/WebKit/LayoutTests/http/tests/security/mixedContent/insecure-formSubmission-in-main-frame-blocked.html
diff --git a/third_party/WebKit/LayoutTests/http/tests/security/mixedContent/insecure-formSubmission-in-main-frame-blocked.html b/third_party/WebKit/LayoutTests/http/tests/security/mixedContent/insecure-formSubmission-in-main-frame-blocked.html
index 7a469e8022c7dda95dfa92d8136380c067a2f7a1..5950a3e38b70f0280de2c41011c171985aef4488 100644
--- a/third_party/WebKit/LayoutTests/http/tests/security/mixedContent/insecure-formSubmission-in-main-frame-blocked.html
+++ b/third_party/WebKit/LayoutTests/http/tests/security/mixedContent/insecure-formSubmission-in-main-frame-blocked.html
@@ -6,7 +6,6 @@ if (window.testRunner) {
     testRunner.dumpAsText();
     testRunner.setCanOpenWindows();
     testRunner.setCloseRemainingWindowsWhenComplete(true);
-    testRunner.overridePreference("WebKitAllowDisplayingInsecureContent", false);
 }
 
 window.addEventListener("message", function (e) {
@@ -15,8 +14,10 @@ window.addEventListener("message", function (e) {
 }, false);
 
 </script>
-<p>This test opens a window that shows a form with "action" pointing to an insecure
-location. We should not trigger a mixed content callback even though the main frame in the window is HTTPS and the form is pointing to insecure content, because we've set the preference to block this.</p>
+<p>This test opens a window that shows a form with "action" pointing to an
+insecure location. We should not trigger a mixed content callback even though
+the main frame in the window is HTTPS and the form is pointing to insecure
+content, because we've set the preference to block this.</p>
 <script>
 window.open("https://127.0.0.1:8443/security/mixedContent/resources/frame-with-insecure-formSubmission.html");
 </script>