Revert of Upgrade insecure requests: Pipe navigational hosts down into nested documents.

Source/core/fetch/ResourceFetcher.cpp

Index: Source/core/fetch/ResourceFetcher.cpp
diff --git a/Source/core/fetch/ResourceFetcher.cpp b/Source/core/fetch/ResourceFetcher.cpp
index 689d8f481624f4b1bb1f63787e7336bf613a2381..4539a04d838e6c3a7fd524cee244a31cc4aa923b 100644
--- a/Source/core/fetch/ResourceFetcher.cpp
+++ b/Source/core/fetch/ResourceFetcher.cpp
@@ -886,17 +886,16 @@
         fetchRequest.mutableResourceRequest().addHTTPHeaderField("Prefer", "return=secure-representation");
 
     if (document()->insecureRequestsPolicy() == SecurityContext::InsecureRequestsUpgrade && url.protocolIs("http")) {
+        // We always upgrade subresource requests and nested frames, we always upgrade form
+        // submissions, and we always upgrade requests whose host matches the host of the
+        // containing document's security origin.
+        //
+        // FIXME: We need to check the document that set the policy, not the current document.
         const ResourceRequest& request = fetchRequest.resourceRequest();
-
-        // We always upgrade requests that meet any of the following criteria:
-        //
-        // 1. Are for subresources (including nested frames).
-        // 2. Are form submissions.
-        // 3. Whose hosts are contained in the document's InsecureNavigationSet.
         if (request.frameType() == WebURLRequest::FrameTypeNone
             || request.frameType() == WebURLRequest::FrameTypeNested
             || request.requestContext() == WebURLRequest::RequestContextForm
-            || document()->insecureNavigationsToUpgrade()->contains(url.host().impl()->hash()))

[Yoav Weiss, 2015/03/10 19:03:05]

Again, here we relied on the existence of
document()->insecureNavigationsToUpgrade() and impl(). Worth to check for it or
assert once this goes back in.

+            || url.host() == document()->securityOrigin()->host())

[Yoav Weiss, 2015/03/10 19:03:05]

Should we assert for document()->securityOrigin() ?

         {
             url.setProtocol("https");
             if (url.port() == 80)