Bug 1153988 - create nsNullPrincipals directly, rather than going thr…

…ough do_CreateInstance; r=smaug

There's a better way to create null principals than
do_CreateInstance("@mozilla.org/nullprincipal;1").  Let's do that and
save ourselves some XPCOM overhead.

docshell/base/nsDocShell.cpp

@@ -1628,7 +1628,7 @@ nsDocShell::LoadURI(nsIURI* aURI,
 
   if (aLoadFlags & LOAD_FLAGS_DISALLOW_INHERIT_OWNER) {
     inheritOwner = false;
-    owner = do_CreateInstance("@mozilla.org/nullprincipal;1");
+    owner = nsNullPrincipal::Create();
   }
 
   uint32_t flags = 0;
@@ -12015,7 +12015,7 @@ nsDocShell::LoadHistoryEntry(nsISHEntry* aEntry, uint32_t aLoadType)
       // Ensure that we have an owner.  Otherwise javascript: URIs will
       // pick it up from the about:blank page we just loaded, and we
       // don't really want even that in this case.
-      owner = do_CreateInstance("@mozilla.org/nullprincipal;1");
+      owner = nsNullPrincipal::Create();
       NS_ENSURE_TRUE(owner, NS_ERROR_OUT_OF_MEMORY);
     }
   }
@@ -13690,8 +13690,7 @@ nsDocShell::GetPrintPreview(nsIWebBrowserPrint** aPrintPreview)
   nsCOMPtr<nsIDocumentViewerPrint> print = do_QueryInterface(mContentViewer);
   if (!print || !print->IsInitializedForPrintPreview()) {
     Stop(nsIWebNavigation::STOP_ALL);
-    nsCOMPtr<nsIPrincipal> principal =
-      do_CreateInstance("@mozilla.org/nullprincipal;1");
+    nsCOMPtr<nsIPrincipal> principal = nsNullPrincipal::Create();
     NS_ENSURE_STATE(principal);
     nsresult rv = CreateAboutBlankContentViewer(principal, nullptr);
     NS_ENSURE_SUCCESS(rv, rv);

dom/base/DOMParser.cpp

@@ -15,6 +15,7 @@
 #include "nsDOMJSUtils.h"
 #include "nsError.h"
 #include "nsPIDOMWindow.h"
+#include "nsNullPrincipal.h"
 #include "mozilla/LoadInfo.h"
 #include "mozilla/dom/BindingUtils.h"
 #include "mozilla/dom/ScriptSettings.h"
@@ -348,8 +349,8 @@ DOMParser::Init(nsIPrincipal* principal, nsIURI* documentURI,
     if (nsContentUtils::IsSystemPrincipal(mPrincipal)) {
       // Don't give DOMParsers the system principal.  Use a null
       // principal instead.
-      mPrincipal = do_CreateInstance("@mozilla.org/nullprincipal;1", &rv);
-      NS_ENSURE_SUCCESS(rv, rv);
+      mPrincipal = nsNullPrincipal::Create();
+      NS_ENSURE_TRUE(mPrincipal, NS_ERROR_FAILURE);
 
       if (!mDocumentURI) {
         rv = mPrincipal->GetURI(getter_AddRefs(mDocumentURI));
@@ -464,9 +465,8 @@ DOMParser::SetUpDocument(DocumentFlavor aFlavor, nsIDOMDocument** aResult)
     NS_ENSURE_TRUE(!mAttemptedInit, NS_ERROR_NOT_INITIALIZED);
     AttemptedInitMarker marker(&mAttemptedInit);
 
-    nsCOMPtr<nsIPrincipal> prin =
-      do_CreateInstance("@mozilla.org/nullprincipal;1", &rv);
-    NS_ENSURE_SUCCESS(rv, rv);
+    nsCOMPtr<nsIPrincipal> prin = nsNullPrincipal::Create();
+    NS_ENSURE_TRUE(prin, NS_ERROR_FAILURE);
 
     rv = Init(prin, nullptr, nullptr, scriptHandlingObject);
     NS_ENSURE_SUCCESS(rv, rv);

dom/base/nsNodeInfoManager.cpp

@@ -29,6 +29,7 @@
 #include "nsCCUncollectableMarker.h"
 #include "nsNameSpaceManager.h"
 #include "nsDocument.h"
+#include "nsNullPrincipal.h"
 
 using namespace mozilla;
 using mozilla::dom::NodeInfo;
@@ -188,9 +189,9 @@ nsNodeInfoManager::Init(nsIDocument *aDocument)
 
   NS_PRECONDITION(!mPrincipal,
                   "Being inited when we already have a principal?");
-  nsresult rv;
-  mPrincipal = do_CreateInstance("@mozilla.org/nullprincipal;1", &rv);
-  NS_ENSURE_TRUE(mPrincipal, rv);
+
+  mPrincipal = nsNullPrincipal::Create();
+  NS_ENSURE_TRUE(mPrincipal, NS_ERROR_FAILURE);
 
   if (aDocument) {
     mBindingManager = new nsBindingManager(aDocument);

dom/datastore/DataStoreDB.cpp

@@ -23,6 +23,7 @@
 #include "nsIDOMEvent.h"
 #include "nsIPrincipal.h"
 #include "nsIXPConnect.h"
+#include "nsNullPrincipal.h"
 
 #define DATASTOREDB_VERSION        1
 #define DATASTOREDB_NAME           "DataStoreDB"
@@ -103,10 +104,9 @@ DataStoreDB::CreateFactoryIfNeeded()
 {
   if (!mFactory) {
     nsresult rv;
-    nsCOMPtr<nsIPrincipal> principal =
-      do_CreateInstance("@mozilla.org/nullprincipal;1", &rv);
-    if (NS_WARN_IF(NS_FAILED(rv))) {
-      return rv;
+    nsCOMPtr<nsIPrincipal> principal = nsNullPrincipal::Create();
+    if (!principal) {
+      return NS_ERROR_FAILURE;
     }
 
     nsIXPConnect* xpc = nsContentUtils::XPConnect();

dom/json/nsJSON.cpp

@@ -411,9 +411,8 @@ nsJSON::DecodeInternal(JSContext* cx,
   }
 
   nsresult rv;
-  nsCOMPtr<nsIPrincipal> nullPrincipal =
-    do_CreateInstance("@mozilla.org/nullprincipal;1", &rv);
-  NS_ENSURE_SUCCESS(rv, rv);
+  nsCOMPtr<nsIPrincipal> nullPrincipal = nsNullPrincipal::Create();
+  NS_ENSURE_TRUE(nullPrincipal, NS_ERROR_FAILURE);
 
   rv = NS_NewInputStreamChannel(getter_AddRefs(jsonChannel),
                                 mURI,

dom/jsurl/nsJSProtocolHandler.cpp

@@ -430,9 +430,8 @@ nsresult nsJSChannel::Init(nsIURI *aURI)
     // and the underlying Input Stream will not be created...
     nsCOMPtr<nsIChannel> channel;
 
-    nsCOMPtr<nsIPrincipal> nullPrincipal =
-      do_CreateInstance("@mozilla.org/nullprincipal;1", &rv);
-    NS_ENSURE_SUCCESS(rv, rv);
+    nsCOMPtr<nsIPrincipal> nullPrincipal = nsNullPrincipal::Create();
+    NS_ENSURE_TRUE(nullPrincipal, NS_ERROR_FAILURE);
 
     // If the resultant script evaluation actually does return a value, we
     // treat it as html.

dom/media/MediaManager.cpp

@@ -47,6 +47,7 @@
 #include "VideoUtils.h"
 #include "Latency.h"
 #include "nsProxyRelease.h"
+#include "nsNullPrincipal.h"
 
 // For PR_snprintf
 #include "prprf.h"
@@ -1007,7 +1008,7 @@ class GetUserMediaStreamRunnable : public nsRunnable
 
     nsCOMPtr<nsIPrincipal> principal;
     if (mPeerIdentity) {
-      principal = do_CreateInstance("@mozilla.org/nullprincipal;1");
+      principal = nsNullPrincipal::Create();
       trackunion->SetPeerIdentity(mPeerIdentity.forget());
     } else {
       principal = window->GetExtantDoc()->NodePrincipal();

dom/plugins/base/nsPluginHost.cpp

@@ -91,6 +91,7 @@
 #include "nsIImageLoadingContent.h"
 #include "mozilla/Preferences.h"
 #include "nsVersionComparator.h"
+#include "nsNullPrincipal.h"
 
 #if defined(XP_WIN)
 #include "nsIWindowMediator.h"
@@ -3117,8 +3118,8 @@ nsresult nsPluginHost::NewPluginURLStream(const nsString& aURL,
     // in this else branch we really don't know where the load is coming
     // from and in fact should use something better than just using
     // a nullPrincipal as the loadingPrincipal.
-    principal = do_CreateInstance("@mozilla.org/nullprincipal;1", &rv);
-    NS_ENSURE_SUCCESS(rv, rv);
+    principal = nsNullPrincipal::Create();
+    NS_ENSURE_TRUE(principal, NS_ERROR_FAILURE);
     rv = NS_NewChannel(getter_AddRefs(channel),
                        url,
                        principal,

dom/plugins/base/nsPluginStreamListenerPeer.cpp

@@ -32,6 +32,7 @@
 #include "GeckoProfiler.h"
 #include "nsPluginInstanceOwner.h"
 #include "nsDataHashtable.h"
+#include "nsNullPrincipal.h"
 
 #define MAGIC_REQUEST_CONTEXT 0x01020304
 
@@ -700,9 +701,8 @@ nsPluginStreamListenerPeer::RequestRead(NPByteRange* rangeList)
     // in this else branch we really don't know where the load is coming
     // from and in fact should use something better than just using
     // a nullPrincipal as the loadingPrincipal.
-    nsCOMPtr<nsIPrincipal> principal =
-      do_CreateInstance("@mozilla.org/nullprincipal;1", &rv);
-    NS_ENSURE_SUCCESS(rv, rv);
+    nsCOMPtr<nsIPrincipal> principal = nsNullPrincipal::Create();
+    NS_ENSURE_TRUE(principal, NS_ERROR_FAILURE);
     rv = NS_NewChannel(getter_AddRefs(channel),
                        mURL,
                        principal,

dom/security/nsCORSListenerProxy.cpp

@@ -35,6 +35,7 @@
 #include "nsIDOMWindowUtils.h"
 #include "nsIDOMWindow.h"
 #include "nsINetworkInterceptController.h"
+#include "nsNullPrincipal.h"
 #include <algorithm>
 
 using namespace mozilla;
@@ -752,7 +753,7 @@ nsCORSListenerProxy::AsyncOnChannelRedirect(nsIChannel *aOldChannel,
         if (NS_SUCCEEDED(rv)) {
           if (!equal) {
             // Spec says to set our source origin to a unique origin.
-            mOriginHeaderPrincipal = do_CreateInstance("@mozilla.org/nullprincipal;1");
+            mOriginHeaderPrincipal = nsNullPrincipal::Create();
             if (!mOriginHeaderPrincipal) {
               rv = NS_ERROR_OUT_OF_MEMORY;
             }

dom/security/nsCSPContext.cpp

@@ -783,9 +783,8 @@ nsCSPContext::SendReports(nsISupports* aBlockedContentSource,
                          nsIContentPolicy::TYPE_CSP_REPORT);
     }
     else {
-      nsCOMPtr<nsIPrincipal> nullPrincipal =
-        do_CreateInstance("@mozilla.org/nullprincipal;1", &rv);
-      NS_ENSURE_SUCCESS(rv, rv);
+      nsCOMPtr<nsIPrincipal> nullPrincipal = nsNullPrincipal::Create();
+      NS_ENSURE_TRUE(nullPrincipal, NS_ERROR_FAILURE);
       rv = NS_NewChannel(getter_AddRefs(reportChannel),
                          reportURI,
                          nullPrincipal,

image/decoders/icon/android/nsIconChannel.cpp

@@ -111,9 +111,8 @@ moz_icon_to_channel(nsIURI* aURI, const nsACString& aFileExt,
   rv = stream->AdoptData((char*)buf, buf_size);
   NS_ENSURE_SUCCESS(rv, rv);
 
-  nsCOMPtr<nsIPrincipal> nullPrincipal =
-    do_CreateInstance("@mozilla.org/nullprincipal;1", &rv);
-  NS_ENSURE_SUCCESS(rv, rv);
+  nsCOMPtr<nsIPrincipal> nullPrincipal = nsNullPrincipal::Create();
+  NS_ENSURE_TRUE(nullPrincipal, NS_ERROR_FAILURE);
 
   return NS_NewInputStreamChannel(aChannel,
                                   aURI,

image/decoders/icon/gtk/nsIconChannel.cpp

@@ -101,9 +101,8 @@ moz_gdk_pixbuf_to_channel(GdkPixbuf* aPixbuf, nsIURI* aURI,
   MOZ_ASSERT(NS_SUCCEEDED(rv));
   NS_ENSURE_SUCCESS(rv, rv);
 
-  nsCOMPtr<nsIPrincipal> nullPrincipal =
-    do_CreateInstance("@mozilla.org/nullprincipal;1", &rv);
-  NS_ENSURE_SUCCESS(rv, rv);
+  nsCOMPtr<nsIPrincipal> nullPrincipal = nsNullPrincipal::Create();
+  NS_ENSURE_TRUE(nullPrincipal, NS_ERROR_FAILURE);
 
   return NS_NewInputStreamChannel(aChannel,
                                   aURI,

image/decoders/icon/qt/nsIconChannel.cpp

@@ -84,9 +84,8 @@ moz_qicon_to_channel(QImage* image, nsIURI* aURI,
   rv = stream->AdoptData((char*)buf, buf_size);
   NS_ENSURE_SUCCESS(rv, rv);
 
-  nsCOMPtr<nsIPrincipal> nullPrincipal =
-    do_CreateInstance("@mozilla.org/nullprincipal;1", &rv);
-  NS_ENSURE_SUCCESS(rv, rv);
+  nsCOMPtr<nsIPrincipal> nullPrincipal = nsNullPrincipal::Create();
+  NS_ENSURE_TRUE(nullPrincipal, NS_ERROR_FAILURE);
 
   return NS_NewInputStreamChannel(aChannel,
                                   aURI,

layout/style/CSSStyleSheet.cpp

@@ -43,6 +43,7 @@
 #include "mozilla/Likely.h"
 #include "mozilla/dom/CSSStyleSheetBinding.h"
 #include "nsComponentManagerUtils.h"
+#include "nsNullPrincipal.h"
 
 using namespace mozilla;
 using namespace mozilla::dom;
@@ -733,7 +734,7 @@ CSSStyleSheetInner::CSSStyleSheetInner(CSSStyleSheet* aPrimarySheet,
   MOZ_COUNT_CTOR(CSSStyleSheetInner);
   mSheets.AppendElement(aPrimarySheet);
 
-  mPrincipal = do_CreateInstance("@mozilla.org/nullprincipal;1");
+  mPrincipal = nsNullPrincipal::Create();
   if (!mPrincipal) {
     NS_RUNTIMEABORT("OOM");
   }

netwerk/base/nsURIChecker.cpp

@@ -137,9 +137,8 @@ NS_IMETHODIMP
 nsURIChecker::Init(nsIURI *aURI)
 {
     nsresult rv;
-    nsCOMPtr<nsIPrincipal> nullPrincipal =
-      do_CreateInstance("@mozilla.org/nullprincipal;1", &rv);
-    NS_ENSURE_SUCCESS(rv, rv);
+    nsCOMPtr<nsIPrincipal> nullPrincipal = nsNullPrincipal::Create();
+    NS_ENSURE_TRUE(nullPrincipal, NS_ERROR_FAILURE);
     rv = NS_NewChannel(getter_AddRefs(mChannel),
                        aURI,
                        nullPrincipal,

netwerk/protocol/viewsource/nsViewSourceChannel.cpp

@@ -60,9 +60,8 @@ nsViewSourceChannel::Init(nsIURI* uri)
     // and sets the right loadInfo right after returning from this function.
     // Until then we follow the principal of least privilege and use
     // nullPrincipal as the loadingPrincipal.
-    nsCOMPtr<nsIPrincipal> nullPrincipal =
-      do_CreateInstance("@mozilla.org/nullprincipal;1", &rv);
-    NS_ENSURE_SUCCESS(rv, rv);
+    nsCOMPtr<nsIPrincipal> nullPrincipal = nsNullPrincipal::Create();
+    NS_ENSURE_TRUE(nullPrincipal, NS_ERROR_FAILURE);
 
     rv = pService->NewChannel2(path,
                                nullptr, // aOriginCharset

parser/html/nsParserUtils.cpp

@@ -36,6 +36,7 @@
 #include "nsTreeSanitizer.h"
 #include "nsHtml5Module.h"
 #include "mozilla/dom/DocumentFragment.h"
+#include "nsNullPrincipal.h"
 
 #define XHTML_DIV_TAG "div xmlns=\"http://www.w3.org/1999/xhtml\""
 
@@ -75,8 +76,7 @@ nsParserUtils::Sanitize(const nsAString& aFromStr,
 {
   nsCOMPtr<nsIURI> uri;
   NS_NewURI(getter_AddRefs(uri), "about:blank");
-  nsCOMPtr<nsIPrincipal> principal =
-    do_CreateInstance("@mozilla.org/nullprincipal;1");
+  nsCOMPtr<nsIPrincipal> principal = nsNullPrincipal::Create();
   nsCOMPtr<nsIDOMDocument> domDocument;
   nsresult rv = NS_NewDOMDocument(getter_AddRefs(domDocument),
                                   EmptyString(),

parser/htmlparser/nsExpatDriver.cpp

@@ -808,9 +808,8 @@ nsExpatDriver::OpenInputStreamFromExternalDTD(const char16_t* aFPIStr,
                        nsIContentPolicy::TYPE_DTD);
   }
   else {
-    nsCOMPtr<nsIPrincipal> nullPrincipal =
-      do_CreateInstance("@mozilla.org/nullprincipal;1", &rv);
-    NS_ENSURE_SUCCESS(rv, rv);
+    nsCOMPtr<nsIPrincipal> nullPrincipal = nsNullPrincipal::Create();
+    NS_ENSURE_TRUE(nullPrincipal, NS_ERROR_FAILURE);
     rv = NS_NewChannel(getter_AddRefs(channel),
                        uri,
                        nullPrincipal,

parser/xml/nsSAXXMLReader.cpp

@@ -496,9 +496,8 @@ nsSAXXMLReader::ParseFromStream(nsIInputStream *aStream,
   rv = EnsureBaseURI();
   NS_ENSURE_SUCCESS(rv, rv);
 
-  nsCOMPtr<nsIPrincipal> nullPrincipal =
-    do_CreateInstance("@mozilla.org/nullprincipal;1", &rv);
-  NS_ENSURE_SUCCESS(rv, rv);
+  nsCOMPtr<nsIPrincipal> nullPrincipal = nsNullPrincipal::Create();
+  NS_ENSURE_TRUE(nullPrincipal, NS_ERROR_FAILURE);
 
   nsCOMPtr<nsIChannel> parserChannel;
   rv = NS_NewInputStreamChannel(getter_AddRefs(parserChannel),

rdf/base/nsRDFXMLParser.cpp

@@ -115,9 +115,8 @@ nsRDFXMLParser::ParseString(nsIRDFDataSource* aSink, nsIURI* aBaseURI, const nsA
     rv = NS_NewCStringInputStream(getter_AddRefs(stream), aString);
     if (NS_FAILED(rv)) return rv;
 
-    nsCOMPtr<nsIPrincipal> nullPrincipal =
-      do_CreateInstance("@mozilla.org/nullprincipal;1", &rv);
-    NS_ENSURE_SUCCESS(rv, rv);
+    nsCOMPtr<nsIPrincipal> nullPrincipal = nsNullPrincipal::Create();
+    NS_ENSURE_TRUE(nullPrincipal, NS_ERROR_FAILURE);
 
     nsCOMPtr<nsIChannel> channel;
     rv = NS_NewInputStreamChannel(getter_AddRefs(channel),