Bug 1518454: Part 1, backend changes, add CSP to loadURIOptions dictionary and pass CSP explicitly from frontend to docshell. r=bz

docshell/base/nsDocShellLoadState.h

@@ -13,6 +13,7 @@
 #include "nsDocShellLoadTypes.h"
 #include "mozilla/net/ReferrerPolicy.h"
 
+class nsIContentSecurityPolicy;
 class nsIInputStream;
 class nsISHEntry;
 class nsIURI;
@@ -78,6 +79,10 @@ class nsDocShellLoadState final {
 
   void SetTriggeringPrincipal(nsIPrincipal* aTriggeringPrincipal);
 
+  nsIContentSecurityPolicy* Csp() const;
+
+  void SetCsp(nsIContentSecurityPolicy* aCsp);
+
   bool InheritPrincipal() const;
 
   void SetInheritPrincipal(bool aInheritPrincipal);
@@ -226,6 +231,13 @@ class nsDocShellLoadState final {
   // SystemPrincipal as the triggeringPrincipal.
   nsCOMPtr<nsIPrincipal> mTriggeringPrincipal;
 
+  // The CSP of the load, that is, the CSP of the entity responsible for causing
+  // the load to occur. Most likely this is the CSP of the document that started
+  // the load. In case the entity starting the load did not use a CSP, then mCsp
+  // can be null. Please note that this is also the CSP that will be applied to
+  // the load in case the load encounters a server side redirect.
+  nsCOMPtr<nsIContentSecurityPolicy> mCsp;
+
   // If a refresh is caused by http-equiv="refresh" we want to set
   // aResultPrincipalURI, but we do not want to overwrite the channel's
   // ResultPrincipalURI, if it has already been set on the channel by a protocol