Bug 1214305 - Part 7: Decide in the child process whether an intercepted channel should go through a secure upgrade; r=mcmanus

This is OK from a security perspective, since this decision only affects
whether the channel will be intercepted with the secure URI in the child
process.  If the intercepting service worker decides to fall back to an
actual network request, we send the request to the parent process with
the original pre-upgrade URI, and the parent process will still be in
charge of whether a network visible HTTP request should be upgraded.

netwerk/protocol/http/HttpChannelChild.cpp

@@ -1736,7 +1736,30 @@ HttpChannelChild::AsyncOpen(nsIStreamListener *listener, nsISupports *aContext)
     return NS_OK;
   }
 
-  if (ShouldIntercept()) {
+  bool isHttps = false;
+  rv = mURI->SchemeIs("https", &isHttps);
+  NS_ENSURE_SUCCESS(rv, rv);
+  nsCOMPtr<nsIPrincipal> resultPrincipal;
+  if (!isHttps && mLoadInfo && mLoadInfo->GetUpgradeInsecureRequests()) {
+      nsContentUtils::GetSecurityManager()->
+        GetChannelResultPrincipal(this, getter_AddRefs(resultPrincipal));
+  }
+  bool shouldUpgrade = false;
+  rv = NS_ShouldSecureUpgrade(mURI,
+                              mLoadInfo,
+                              resultPrincipal,
+                              mPrivateBrowsing,
+                              mAllowSTS,
+                              shouldUpgrade);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  nsCOMPtr<nsIURI> upgradedURI;
+  if (shouldUpgrade) {
+    rv = GetSecureUpgradedURI(mURI, getter_AddRefs(upgradedURI));
+    NS_ENSURE_SUCCESS(rv, rv);
+  }
+
+  if (ShouldIntercept(upgradedURI)) {
     mResponseCouldBeSynthesized = true;
 
     nsCOMPtr<nsINetworkInterceptController> controller;