Bug 1948889 - Simplify SRICheck by getting location from http referrer info. r=freddyb,tschuster

The referrer info is more directly what we want (what triggered this
load).

I could add this information for non-http channels, but I think it's
probably not worth it. This is useful because it's thread-safe, which
allows me to support off-main-thread parsing of stylesheets that contain
SRI metadata.

It also simplifies the API and avoids getting URIs around in non-error
code paths.

Differential Revision: https://phabricator.services.mozilla.com/D238612

dom/script/ScriptLoader.cpp

@@ -931,12 +931,8 @@ nsresult ScriptLoader::PrepareIncrementalStreamLoader(
     ScriptLoadRequest* aRequest) {
   UniquePtr<mozilla::dom::SRICheckDataVerifier> sriDataVerifier;
   if (!aRequest->mIntegrity.IsEmpty()) {
-    nsAutoCString sourceUri;
-    if (mDocument->GetDocumentURI()) {
-      mDocument->GetDocumentURI()->GetAsciiSpec(sourceUri);
-    }
     sriDataVerifier = MakeUnique<SRICheckDataVerifier>(aRequest->mIntegrity,
-                                                       sourceUri, mReporter);
+                                                       aChannel, mReporter);
   }
 
   RefPtr<ScriptLoadHandler> handler =
@@ -3837,13 +3833,7 @@ nsresult ScriptLoader::VerifySRI(ScriptLoadRequest* aRequest,
   if (!aRequest->mIntegrity.IsEmpty() && NS_SUCCEEDED((rv = aSRIStatus))) {
     MOZ_ASSERT(aSRIDataVerifier);
     MOZ_ASSERT(mReporter);
-
-    nsAutoCString sourceUri;
-    if (mDocument && mDocument->GetDocumentURI()) {
-      mDocument->GetDocumentURI()->GetAsciiSpec(sourceUri);
-    }
-    rv = aSRIDataVerifier->Verify(aRequest->mIntegrity, channel, sourceUri,
-                                  mReporter);
+    rv = aSRIDataVerifier->Verify(aRequest->mIntegrity, channel, mReporter);
     if (channelRequest) {
       mReporter->FlushReportsToConsole(
           nsContentUtils::GetInnerWindowID(channelRequest));