Revert of Mixed Content: Move subframe checks into ResourceFetcher.

Source/core/loader/DocumentLoader.cpp

Index: Source/core/loader/DocumentLoader.cpp
diff --git a/Source/core/loader/DocumentLoader.cpp b/Source/core/loader/DocumentLoader.cpp
index 61dd9a6f06e2332186c2d879390caff31ce4a916..cd27caf6fa031a79a08d7a27c8725564e91781c6 100644
--- a/Source/core/loader/DocumentLoader.cpp
+++ b/Source/core/loader/DocumentLoader.cpp
@@ -376,6 +376,14 @@
     if (newRequest.cachePolicy() == UseProtocolCachePolicy && isRedirectAfterPost(newRequest, redirectResponse))
         newRequest.setCachePolicy(ReloadBypassingCache);
 
+    // If this is a sub-frame, check for mixed content blocking against the parent frame.
+    if (Frame* parent = m_frame->tree().parent()) {
+        if (parent->isLocalFrame() && !toLocalFrame(parent)->loader().mixedContentChecker()->canFrameInsecureContent(toLocalFrame(parent)->document()->securityOrigin(), newRequest.url())) {
+            cancelMainResourceLoad(ResourceError::cancelledError(newRequest.url()));
+            return;
+        }
+    }
+
     m_request = newRequest;
 
     if (redirectResponse.isNull())