Bug 1580782 - Expose SchemeIs on nsIPrincipal r=ckerschb

Differential Revision: https://phabricator.services.mozilla.com/D45653

caps/BasePrincipal.cpp

@@ -410,6 +410,18 @@ BasePrincipal::GetIsAddonOrExpandedAddonPrincipal(bool* aResult) {
   return NS_OK;
 }
 
+NS_IMETHODIMP
+BasePrincipal::SchemeIs(const char* aScheme, bool* aResult) {
+  *aResult = false;
+  nsCOMPtr<nsIURI> prinURI;
+  nsresult rv = GetURI(getter_AddRefs(prinURI));
+  if (NS_FAILED(rv) || !prinURI) {
+    return NS_OK;
+  }
+  *aResult = prinURI->SchemeIs(aScheme);
+  return NS_OK;
+}
+
 NS_IMETHODIMP
 BasePrincipal::GetOriginAttributes(JSContext* aCx,
                                    JS::MutableHandle<JS::Value> aVal) {

caps/BasePrincipal.h

@@ -116,6 +116,7 @@ class BasePrincipal : public nsJSPrincipals {
   NS_IMETHOD GetIsContentPrincipal(bool* aResult) override;
   NS_IMETHOD GetIsExpandedPrincipal(bool* aResult) override;
   NS_IMETHOD GetIsSystemPrincipal(bool* aResult) override;
+  NS_IMETHOD SchemeIs(const char* aScheme, bool* aResult) override;
   NS_IMETHOD GetIsAddonOrExpandedAddonPrincipal(bool* aResult) override;
   NS_IMETHOD GetOriginAttributes(JSContext* aCx,
                                  JS::MutableHandle<JS::Value> aVal) final;

caps/nsIPrincipal.idl

@@ -180,6 +180,22 @@ interface nsIPrincipal : nsISerializable
      */
     readonly attribute ACString origin;
 
+    /**
+    * Checks if the Principal's URI Scheme matches with the parameter
+    *
+    * @param scheme    The scheme to be checked
+    */
+    boolean schemeIs(in string scheme);
+
+    // Nicer, C++ Callable Version of SchemeIs
+    %{C++
+      inline bool SchemeIs(const char* aScheme) {
+        bool ret;
+        SchemeIs(aScheme, &ret);
+        return ret;
+      }
+    %}
+
     /**
      * The base part of |origin| without the concatenation with |originSuffix|.
      * This doesn't have the important invariants described above with |origin|,